Duck Fat-Potato Galette with Caraway and Sweet Onions
- 4 tbsp. (1/2 stick) unsalted butter, melted, divided, plus more for pan
- 1/2 tsp. caraway seeds
- 2 tbsp. rendered duck or bacon fat, melted
- 1 tsp. (or more) kosher salt
- 1/2 tsp. freshly ground black pepper
- 2 lb medium Bambino potatoes, unpeeled, cut into 1/8\'-thick slices with a mandoline or V-slicer
- 1 small sweet onion (such as Maui), very thinly sliced
- Arrange a rack in middle of oven; preheat to 425°. Brush a foil- or parchment-lined baking sheet with butter; set springform ring on top.
- Toast caraway in a small skillet over medium heat until fragrant, about 1 minute. Let cool. Place in a resealable plastic bag; crush with a rolling pin or bottom of a skillet. Place in a large bowl. Add duck fat, 2 Tbsp. butter, 1 tsp. salt, and pepper. Add potatoes; toss to coat.
- Arrange 1/4 of potatoes in an even layer inside ring on baking sheet, overlapping as needed. Toss onion in a large bowl with 1 Tbsp. melted butter. Arrange 1/3 of onion over potatoes. Repeat layers twice more, finishing with a layer of potatoes. Carefully remove ring.
- Bake until potatoes are tender, about 45 minutes. Brush with 1 Tbsp. butter. Bake until edges of potatoes are deep golden and top is crisp, 5–10 minutes longer.
- Run a thin spatula under galette to loosen from foil. Slide onto a platter. Season with salt, if desired