Melted Onions

Ingredients

6 medium onions—each 3 inches in diameter (2½ pounds total), halved crosswise through the center (not the root and stem), ends trimmed by ¼ inch
½ teaspoon kosher salt
3 teaspoons freshly ground black pepper
2 tablespoons ghee or unsalted butter, melted (or your preferred cooking oil)

With a rack in the top position, preheat the oven to 425°F
Place the onion halves cut-side up in the cups of a 12-cup muffin tin. Sprinkle the onions with the salt and pepper.
Roast until the onions have softened slightly and sunk into the cups, 18 to 20 minutes.
Brush with the ghee (or other cooking oil) and return to the oven.
Bake until extremely soft and golden brown, 35 to 40 minutes more.
The onions can be kept in the refrigerator in an airtight container for up to 4 days.