Pork and Kohlrabi Gratin with Sage
Thin slices of kohlrabi layered with browned pork, sage, and onion under a pumpkin and bone broth sauce, baked covered and then open until the top browns.
Why You'll Love This Recipe
A gratin is the dish I miss most when I am cooking without dairy, and this is the one that finally satisfied me. The trick turned out to be pumpkin puree loosened with bone broth, which bakes down into a sauce that clings to the slices and goes glossy on top rather than watery. I make it on Sunday for a house full of people, and I make it in October when the oven being on for an hour is a feature. It comes out of the oven looking like something you would put in the middle of a table, which is not a small thing when dinner has been plain for a while.
The slices decide everything. Kohlrabi is dense, so cut it at an eighth of an inch, which is thin enough to go fully tender in the oven and thick enough to stay in distinct layers. A mandoline does this in two minutes and a sharp knife does it in eight. Brown the pork properly first, in a hot pan, left alone until a crust forms, because everything you build on top of that is a wet cook and there will be no browning after this point. Then it goes together like any layered bake: kohlrabi, pork, sauce, and repeat. Season lightly as you build rather than all at the end, so no single layer arrives flat.
Covered for the first forty-five minutes, open for the last twenty-five. The foil traps steam so the kohlrabi cooks through, and taking it off lets the top layer dry out and brown at the edges, which is the whole reason a gratin is worth making. Let it sit for ten minutes before you cut it or the layers slide apart on the spatula. The chives go on after that rest rather than before, since they shrivel to nothing on a surface straight out of the oven. Between the pork and the kohlrabi there is real protein and real fiber in a square of this, and sage, thyme, and chives keep it tasting like autumn cooking rather than a plain casserole.
Ingredients
- 1 1/2 lb ground pork
- 3 large kohlrabi bulbs (about 2 lb), peeled and sliced 1/8 inch thick
- 1 large yellow onion, thinly sliced
- 6 cloves garlic, minced
- 1 cup pumpkin puree
- 1 1/2 cups chicken bone broth
- 2 tbsp olive oil, divided
- 2 tsp dried rubbed sage
- 1 tbsp fresh thyme leaves
- 2 tsp apple cider vinegar
- 3 tbsp chopped fresh chives
- 1 1/2 tsp fine sea salt, divided
Instructions
- Prepare the kohlrabi: Heat the oven to 375°F (190°C). Cut the stems and the woody base off each bulb and take the skin off with a paring knife, going deep enough to remove the fibrous layer just underneath, which stays tough no matter how long it bakes. Slice the bulbs 1/8 inch thick, on a mandoline if you have one.
- Brown the pork: Heat 1 tablespoon of the olive oil in a large skillet over medium-high. Add the ground pork in large clumps with 1/2 teaspoon of the salt and leave it undisturbed for 4 minutes so a crust forms, then break it up and cook 3 to 4 minutes more, until no pink remains. Lift the pork into a bowl.
- Cook the onion and herbs: Add the remaining tablespoon of oil to the same pan with the onion and 1/4 teaspoon salt, and cook over medium for 6 minutes until soft and golden at the edges. Stir in the garlic, sage, and thyme and cook 1 minute more, then take the pan off the heat and stir in the cider vinegar and the pork.
- Make the sauce: Whisk the pumpkin puree and the bone broth together in a bowl with 1/2 teaspoon of the salt until completely smooth and pourable, about the thickness of heavy cream. Lumps of pumpkin will not spread evenly between the layers, so keep whisking until the color is uniform.
- Layer the dish: Oil a 9-inch square baking dish. Lay down a third of the kohlrabi in overlapping rows, season with a pinch of the remaining salt, spread over half the pork mixture, and pour on a third of the sauce. Repeat, then finish with a neat top layer of kohlrabi and the last of the sauce, spread to the corners.
- Bake, uncover, and rest: Cover tightly with foil and bake for 45 minutes. Remove the foil and bake for 25 to 30 minutes more, until the top is browned at the edges and a knife slides through the center with no resistance. Let it stand for 10 minutes, then scatter the chives over the top and cut into squares.
Variations
- Ground lamb: Swap the pork for ground lamb and the sage for chopped fresh rosemary when you want a richer, more herbal bake.
- Bacon on top: Lay strips of bacon over the final layer before the foil comes off so they crisp during the open bake and season the whole dish.
- Greens between the layers: Wilt a few handfuls of spinach or chard and press them dry, then add a thin layer over the pork for something dark green in each square.
- Apple and sage: Cook a thinly sliced apple with the onion for a sweeter version that leans harder into the sage.
- Meatless middle: Leave the pork out and use mushrooms browned hard in its place, keeping the same sauce and the same bake.
Storage & Leftovers
Cooled and covered, this keeps in the refrigerator for up to 4 days and slices far more neatly on day two, once the sauce has set around the layers. Cut it into portions before you store it so you are not carving a cold dish, and keep the chives for the moment you serve it.
Reheat squares in a 350°F (175°C) oven for 15 minutes, uncovered, which brings the top back to something close to its first day. The microwave does it in 2 minutes and works perfectly well, though the top goes soft and you lose the browned edge that makes the dish what it is.
It freezes in portions for up to 3 months, wrapped tightly and thawed overnight in the refrigerator before reheating. Kohlrabi holds its shape through freezing better than most vegetables, and the pumpkin sauce comes back together as it warms rather than splitting the way a cream sauce would.
Notes & Tips
- Peel past the skin: There is a woody layer beneath the surface of a kohlrabi bulb that stays chewy through an hour in the oven. A paring knife takes it off cleanly where a vegetable peeler skims over it.
- One eighth of an inch: This is the measurement the recipe rests on. Thicker slices stay firm in the middle of the bake and thinner ones melt into the sauce and lose the layers.
- Brown the pork before it goes in: Everything after this step is a moist cook. Meat added raw to the layers will be gray and slightly bouncy, with none of the flavor a crust gives you.
- Whisk the sauce smooth: Pumpkin straight from the can is stiff, and a lumpy sauce leaves dry patches between the layers. It should pour off the whisk in a ribbon.
- Foil first, then bare: Baking it uncovered the whole time dries the top before the middle is tender. The covered stretch cooks it through, and the open stretch is where the browning happens.
- Rest before cutting: Ten minutes on the counter lets the sauce settle and grip the layers. Cut it straight from the oven and the first square will arrive on the plate in pieces.
Nutrition & Mindful Eating
- The pork, the kohlrabi, and the pumpkin sauce each carry part of this dish. The meat gives it substance and savor, the sliced bulbs give it structure and something to chew, and the sauce holds the layers together and carries the sage and garlic into every one of them.
- Ground pork browned hard is what the whole bake is built on, and the fat it renders seasons the kohlrabi around it. The meat brings protein, zinc, and B vitamins including thiamin, which pork carries more of than most foods.
- Kohlrabi is a cabbage-family bulb with a mild, faintly sweet flavor, and it stays in distinct tender layers through an hour in the oven. It holds a good amount of vitamin C along with the fiber that keeps a meat-heavy square feeling balanced.
- Pumpkin puree whisked into the broth is what thickens the sauce into something glossy that clings to every slice, and it brings beta-carotene along with the deep orange color it gives the finished dish.
- Sage, thyme, garlic, and a spoonful of cider vinegar are the entire seasoning, and the chives scattered over the hot dish at the end give it a fresh onion note that keeps the bake from tasting heavy.
- As you eat, run your fork down through the layers so you get sauce, pork, and kohlrabi in one bite, and notice partway through the square whether the warmth of the sage has already made this feel like enough.
Frequently Asked Questions
What can I use in place of kohlrabi?
Rutabaga, turnip, and celeriac all slice and bake the same way at the same weight, though rutabaga is sweeter and celeriac is more savory. Whatever you choose, keep the slices at an eighth of an inch. Thicker slices need another 15 minutes under the foil to go tender.
Does the pumpkin make it taste like a sweet dish?
No. A cup of puree loosened with bone broth reads as body and color rather than as pumpkin, especially against browned pork, garlic, and sage. If you want it more savory still, use a full 2 cups of broth and a scant three quarters cup of the puree.
Can I assemble it ahead of time?
Yes. Build the whole dish up to a day ahead, cover it, and refrigerate. Add about 10 minutes to the covered baking time since it starts cold. This is also how I get it onto the table on a weeknight, since the assembly is the only part that takes real time.
Does this fit an AIP elimination phase?
It does. There are no grains, legumes, dairy, eggs, nuts, seeds, or nightshades in it, and the seasoning is onion, garlic, sage, thyme, chives, and cider vinegar. Check that your pumpkin is plain puree rather than pie filling, which carries sugar and spices that do not belong here.