01 -
Trim off any browned leaves and the base of the stalk from the Brussels sprouts, then halve them lengthwise. Grate the Gruyère and Parmesan cheeses. Preheat the oven to 400°F and set the rack in the middle position.
02 -
Heat olive oil and butter in an oven-safe skillet over medium-high heat until hot. Add the Brussels sprouts and sauté for 8 minutes, turning occasionally until they develop a golden-brown exterior.
03 -
Remove the skillet from heat. Stir in the minced garlic, heavy cream, and half of the grated Gruyère cheese until evenly combined.
04 -
Sprinkle the remaining Gruyère and all of the Parmesan cheese over the Brussels sprouts. Transfer the skillet to the oven and roast for 15 to 20 minutes until the sprouts are tender yet crisp. For a golden bubbly top, broil for 1 to 2 minutes, watching carefully.
05 -
Season with salt and freshly ground black pepper to taste. Serve immediately to enjoy the creamy texture before the cheese hardens.