Caramelized Shallot Fontina Potato Gratin Tips, FAQ & printable recipe

Tips for success

For the best flavor, take the time to properly caramelize the shallots – cook them low and slow in butter until they are deep golden brown and jammy.

This can be done up to three days in advance. If you're short on time, store-bought fried shallots can be used in the layers, but they won't provide the same sweet, savory depth.

When layering, don't overfill the slow cooker – leave at least an inch of headspace to allow the cream to bubble and the cheese to melt without overflowing.

If you have extra potatoes, cook them in a separate dish or adjust the cooking time. For a crisper top, you can transfer the finished gratin to a broiler for 2-3 minutes, but watch it closely to avoid burning.

Variations

• Herbed Variation: Replace the fresh rosemary with 1 tablespoon each of fresh thyme and sage, chopped. These herbs pair beautifully with Fontina and shallots, adding an earthy, aromatic note.
• Cheese Swap: Use Gruyère or white cheddar instead of Fontina for a slightly different flavor profile. Gruyère adds a nutty, salty depth, while white cheddar brings a sharper bite.
• Add Bacon: For a smoky twist, layer 6 slices of cooked, crumbled bacon between the potato layers. This adds a savory crunch and richness that complements the shallots and cheese.
• Vegetable Boost: Add a layer of thinly sliced leeks or fennel along with the shallots for extra sweetness and texture. Sauté the leeks or fennel until soft before layering.

Storage and make-ahead

Fridge

Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat gently to maintain creaminess.

Freezer

Freeze the baked gratin in a freezer-safe container for up to 2 months. Thaw overnight in the refrigerator before reheating.

Reheat

Reheat in a 350°F oven for 15-20 minutes, or in the microwave in 1-minute intervals. Add a splash of cream if needed.

Store leftover gratin in an airtight container in the refrigerator for up to 4 days. The flavors will meld and deepen overnight. Reheat individual portions in the microwave or in a 350°F oven until warmed through. If the gratin seems dry after reheating, add a splash of cream or milk before warming.

This gratin is ideal for making ahead. Assemble the layers in the slow cooker insert, cover, and refrigerate for up to 24 hours before cooking.

When ready to cook, add an extra 30 minutes to the cooking time to account for the cold start. The caramelized shallots can also be made up to 3 days ahead and stored in the refrigerator.

Serving ideas

Serve this gratin as a luxurious side dish alongside roasted chicken, beef, or pork. It also shines as a vegetarian main course when paired with a green salad and crusty bread. The creamy, cheesy layers are indulgent enough to stand on their own, making it a versatile addition to any meal.

Garnish each serving with a sprinkle of crispy fried shallots and a few fresh rosemary needles for a pop of color and texture.

The crispy shallots add a delightful crunch that contrasts with the creamy potatoes. This dish is best enjoyed warm, straight from the slow cooker, but it also holds well on a buffet table for a while.

Frequently asked questions

Recipe card

Caramelized Shallot Fontina Potato Gratin

Prep 15 minCook 4 h 30 minRest 10 minTotal 4 h 55 minServes 8

Ingredients

• 4 lb red-skin potatoes, thinly sliced
• 1 1/2 cups caramelized shallots
• 2 cups shredded Fontina cheese
• 1 1/2 cups heavy cream
• 2 tbsp fresh rosemary, chopped
• 1 tsp kosher salt
• 1/2 tsp black pepper
• crispy fried shallots, for serving
• fresh rosemary needles, for serving

Instructions

1. Lightly coat the insert of a 6-quart slow cooker with nonstick spray or a thin layer of butter. This helps the gratin release cleanly and prevents sticking.
2. Arrange one-third of the sliced red potatoes evenly in the bottom of the slow cooker. Sprinkle with a pinch of salt and pepper.
3. Scatter one-third of the caramelized shallots over the potatoes, then sprinkle with one-third of the shredded Fontina and a little chopped rosemary.
4. Repeat the layering process two more times, finishing with a final layer of potatoes, then the remaining shallots, Fontina, and rosemary.
5. Pour the heavy cream evenly over the top, allowing it to seep down between the layers. Season with any remaining salt and pepper.
6. Cover the slow cooker and cook on LOW for 4 1/2 hours, until the potatoes are tender when pierced with a fork and the cheese is bubbly and golden around the edges.
7. After 4 1/2 hours, insert a fork into the center of the gratin. The potatoes should be completely tender with no resistance. If not, continue cooking in 15-minute increments.
8. Turn off the slow cooker and let the gratin rest, uncovered, for 10 minutes. This allows the sauce to set slightly and makes it easier to slice.
9. Slice the gratin into squares or wedges directly from the slow cooker. Top each serving with crispy fried shallots and a few fresh rosemary needles.

Contains: milk

Estimated nutrition per serving

Calories

420

Protein

12 g

Carbohydrates

35 g

Fat

27 g

Automatic estimate from the ingredient list, not laboratory-verified.