Fennel and Sweet Potato Gratin

This potato gratin honestly took some trial and error to get right. My first attempt involved caramelizing the onions and fennel before mixing them with the cream, but after an hour and a half in the oven, they’d cooked down too much and practically disappeared. The second version skipped that step and let everything caramelize together in the oven instead. Much better.

I also tested peeling versus not peeling the potatoes. Turns out, leaving the skins on works fine and saves time. Between slicing everything thin on a mandoline and arranging the layers, there’s already enough work involved. No point adding unnecessary steps.

About that mandoline: use the guard and go slow, especially when you get near the end of each potato. The blades are sharp and will bite if you’re distracted or rushing. A cut-resistant glove is worth considering if you’re new to using one. If you have knife skills precise enough to get paper-thin, even slices, go for it, but the mandoline makes this much easier. Uniform thickness matters here so everything cooks at the same rate.

The finished gratin is absolutely worth the effort. The potatoes turn tender and luscious, with crispy edges on top. Red, white, and sweet potatoes together taste wintery without being too sweet. The onions and fennel mellow as they cook, going from sharp to caramelized and slightly sweet. Gruyère and Parmesan obviously adds decadent cheesiness. This works as a side for any cold-weather meal that needs something substantial on the plate.

Step by Step Guide to Making Fennel and Sweet Potato Gratin

1. Prep Oven and Cheeses:

   • Preheat oven to 400°F. Mix comte and parmesan cheeses, setting aside 1/3 for topping. In the larger cheese portion, mix in cream, salt, pepper, garlic, sage, and thyme.

2. ---

   Slice Vegetables:

   • Slice potatoes, fennel, and onions using a mandoline for even thickness at about 1/8 inch (3mm). Combine in a large bowl.

3. ---

   Combine with Cream Mixture:

   • Toss vegetables with cream and cheese mixture, ensuring each slice is coated.

4. ---

   Prepare Baking Dish:

   • Butter a large casserole dish or 12″ cast iron skillet. Neatly stack potato, onion, and fennel slices in the dish vertically.

5. ---

   Bake:

   • Cover and bake for 30 minutes. Uncover and bake for another 30 minutes. Sprinkle with reserved cheese and bake until golden brown, about 30 minutes more.

6. ---

   Rest and Serve:

   • Let the gratin rest for at least 15 minutes before serving.

NOTES

• Cheese Choice: The nutty flavor of Comte or Gruyere adds depth.
• Mandoline Use: Ensure uniform thickness for even cooking.
• Seasoning: Don’t shy away from the salt; it’s crucial for flavoring this hearty dish.
• Resting Time: Allows the gratin to set and flavors to meld.

Fennel and Sweet Potato Gratin

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5 Stars 4 Stars 3 Stars 2 Stars 1 Star

5 from 3 reviews

• Author: Tux Loerzel
• Total Time: 110 minutes
• Yield: Serves 6
• Diet: Omnivore

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Description

Tender potatoes and crunchy edges make this gratin irresistible. A mix of cheeses and herbs creates a rich, comforting side dish.

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Ingredients

Units USM Scale 1x2x3x

• 1 cups (237 ml) Comte Cheese
• 0.5 cups (118 ml) Parmesan Cheese
• 2 cups (473 ml) heavy cream
• 1 tbsp Kosher salt
• 1.5 tsp ground Black Pepper
• 4 cloves minced garlic
• 1.5 tbsp finely chopped fresh sage
• 2 tsp finely chopped fresh thyme
• 1 lbs (454 g) red potatoes
• 1 lbs (454 g) white potatoes
• 1.5 lbs (680 g) sweet potatoes
• 0.75 lbs (340 g) fennel bulbs
• 0.5 lbs (227 g) onions
• 2 tbsp softened butter

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Instructions

1. Preheat oven to 400°F (204°C).
2. Mix comte and parmesan cheeses, setting aside 1/3 for topping. Mix the remaining cheese with cream, salt, pepper, garlic, sage, and thyme.
3. Slice potatoes, fennel, and onions using a mandoline for even thickness. Combine in a large bowl.
4. Toss vegetables with the cream and cheese mixture, ensuring each slice is coated.
5. Butter a large casserole dish or 12″ cast iron skillet.
6. Neatly stack potato, onion, and fennel slices in the dish vertically.
7. Cover and bake for 30 minutes. Uncover and bake for another 30 minutes.
8. Sprinkle with reserved cheese and bake until golden brown, about 30 minutes more.
9. Let the gratin rest for at least 15 minutes before serving.

Notes

• For optimal flavor, use a mandoline slicer to ensure even vegetable thickness, resulting in uniform cooking.
• To reduce richness, substitute half-and-half for some of the heavy cream.
• Store leftover gratin in an airtight container in the refrigerator for up to 3 days; reheat gently in the oven or microwave.

• Prep Time: 20 minutes
• Cook Time: 90 minutes
• Category: Side Dish
• Method: Roasting
• Cuisine: French-Inspired

Nutrition

• Serving Size: 1 cup
• Calories: 350
• Sugar: 5
• Sodium: 450
• Fat: 25
• Saturated Fat: 15
• Unsaturated Fat: 8
• Carbohydrates: 30
• Fiber: 4
• Protein: 10
• Cholesterol: 80

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Provolone Potatoes au Gratin

Raclette Potatoes au Gratin

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