- 3 tablespoons butter, divided
- 4 large portobello mushrooms, stems removed
- 1 dash garlic powder
- 1 tablespoon butter
- 2 pounds scallops
- 1 cup Japanese mayonnaise, such as Kewpie brand
- 1/2 teaspoon chili-garlic sauce, or to taste
- 2 tablespoons green onions, chopped
- Melt 1/4 of the 3 tablespoon of butter in a skillet over medium-high heat, add a mushroom cap, and cook on both sides until completely soft to the center, about 3 minutes. Repeat with remaining butter and mushrooms, and place the cooked mushrooms upside-down on an aluminum foil-lined baking sheet; sprinkle with garlic powder.
- Preheat the oven's broiler and set the oven rack at about 6 inches from the heat source.
- Melt the remaining 1 tablespoon of butter in a skillet over medium-high heat. Add the scallops, and cook until just firm, and lightly browned on both sides. Divide scallops among mushroom caps. Stir together mayonnaise and chili sauce in a small bowl, and spoon over the scallops.
- Broil until the mayonnaise has developed brown patches and is hot, 3 to 5 minutes. Sprinkle with green onions to serve.