Ingredients
Original recipe (1X) yields 8 servings
- 2 pounds sweet potatoes, peeled and sliced 1-inch thick
- 1½ tablespoons extra-virgin olive oil
- 1 tablespoon melted unsalted butter plus 1 tablespoon cold unsalted butter, divided
- 1 tablespoon chopped fresh thyme, plus leaves for garnish
- ½ teaspoon ground pepper, plus more for garnish
- ½ teaspoon salt, divided
- 3 medium sweet onions, sliced
- ½ cup water, plus more as needed
- 1½ tablespoons sherry vinegar
- 1¼ cups reduced-sodium beef broth
- 5 cloves garlic, minced
- ½ cup shredded Gruyère cheese
Directions
Position rack in upper third of oven; preheat to 500°F. Combine sliced sweet potatoes, 1½ tablespoons oil, 1 tablespoon melted butter, 1 tablespoon thyme, ½ teaspoon pepper and ¼ teaspoon salt in a large bowl; toss well to coat. Arrange in a single layer in a 9-by-13-inch metal baking pan (do not use a glass pan, which could shatter). Roast, flipping once, until browned, 25 to 30 minutes.
Meanwhile, combine sliced onions and ½ cup water in a large skillet. Cover and cook over medium-high heat, stirring occasionally, until the onions are softened and the water has evaporated, about 15 minutes. Uncover and cook, stirring often, until the onions are deeply golden brown and jammy, 20 to 25 minutes, adding more water as needed if the pan becomes dry. Add 1½ tablespoons vinegar; cook, stirring constantly and scraping up any browned bits, until the liquid has evaporated, about 1 minute. Remove from heat.
Combine 1¼ cups broth and the minced garlic in a small bowl; carefully pour over the sweet potatoes. Continue roasting, undisturbed, until some of the broth is absorbed and the sweet potatoes are very tender, about 7 minutes.
Transfer the pan to a heatproof work surface. Immediately add the remaining 1 tablespoon cold butter. Gently shake the pan back and forth until the butter is melted and emulsified with the remaining liquid. Set the oven to broil.
Top the sweet potatoes with the onions and ½ cup Gruyère. Broil until the cheese is melted and lightly browned, about 5 minutes. Sprinkle with the remaining ¼ teaspoon salt. Garnish with thyme leaves and/or additional pepper, if desired.
Source: https://www.eatingwell.com/french-onion-melting-sweet-potatoes-12111275
