Turnips

Fresh turnips (about 2½ pounds)

• Choose medium-sized turnips that feel heavy for their size. Smaller to medium turnips tend to be sweeter and less bitter than very large ones. The flesh should be firm and white with no soft spots or browning. If the greens are still attached and look fresh, that’s a good sign the turnips were recently harvested.

Dairy and fats

Heavy cream (2 cups)

• This forms the backbone of the sauce. Heavy cream gives the gratin its signature richness and helps the turnips cook gently and evenly.

Whole milk (½ cup)

• Adding a bit of milk lightens the cream slightly so the dish doesn’t feel overly heavy.

Unsalted butter (2 tablespoons)

• Used for greasing the baking dish and adding subtle richness to the sauce.

Cheese

Gruyère cheese (8 ounces, freshly grated)

• Gruyère is ideal here because it melts smoothly and brings a nutty slightly sweet flavor that pairs beautifully with turnips. Avoid pre-shredded cheese, which often contains anti-caking agents that prevent smooth melting.

Aromatics and seasoning

Garlic (3 cloves, finely minced)

• Garlic infuses the cream with savory depth without overpowering the delicate turnips.

Shallot (1 small, finely chopped)

• Shallot adds a gentle onion flavor that’s sweeter and more nuanced than a regular onion.

Salt (1½ teaspoons)

• Essential for bringing out the natural sweetness of the turnips.

Black pepper (¾ teaspoon, freshly ground)

• Adds warmth and subtle spice.

Nutmeg (¼ teaspoon, freshly grated)

• A classic gratin seasoning that enhances the creamy sauce and cheese.

Optional finishing touches

Fresh thyme leaves (1 teaspoon)

• Sprinkled on top before baking or just before serving for a subtle herbal note.

Breadcrumbs (½ cup, optional)

• If you like a crispier top breadcrumbs mixed with a little melted butter can be added before baking.