Sweet Potato Gratin with Caramelized Onions

Ingredients

• 1 cup (4 oz.) pecan halves, toasted
• 2 cups heavy cream
• ½ Tbs. freshly grated orange zest (from 1 orange)
• ¹/₈ tsp. cayenne
• 2 Tbs. freshly grated Parmigiano-Reggiano
• 2 Tbs. fresh breadcrumbs
• 2 oz. (4 Tbs.) unsalted butter; more for the baking dish
• + 5 more ingredients
• • 2 lb. yellow onions, thinly sliced (about 6 cups)
  • ½ tsp. kosher salt; more to taste
  • ½ tsp. freshly ground black pepper, more to taste
  • 4 lb. sweet potatoes (about 5 medium)
  • 3 sprigs fresh thyme

Heat the butter in a heavy-based 12-inch skillet over medium heat until it begins to foam. Add the onions, reduce the heat to medium low, and cook slowly, stirring occasionally, until the onions are soft and nicely browned, 30 to 40 minutes. Season with the 1/2 tsp. each salt and pepper. Remove f...

View full recipe at Fine Cooking