I call these House Portobello Burgers because, if I owned a cafe, these would be on the menu, and that’s what I’d call them. They’re so yummy they could be a signature burger at any good establishment. Avocado provides a creamy texture, horseradish mustard gives it a spicy kick, and the Portobello mushrooms, onions, and peppers give it a classic flavor combination.
- 4 large - Portobello mushroom caps, stems removed
- 1 medium - red bell pepper, cut into strips
- 1/2 medium - onion, cut into strips
- 1 medium - avocado, skin and pit removed, mashed
- 4 - whole-grain burger buns
- 8 leaves - leaf lettuce, for topping
- 2 Tbs - horseradish mustard, for topping
- Preheat the oven to 400 °F. Line a baking sheet with parchment paper. Wipe the mushrooms clean of any dirt and remove the stems. Place the mushrooms on the prepared baking sheet and bake for 10 minutes. Turn the mushrooms over, and bake another 10 minutes.
- While the mushrooms are baking, sauté the sliced onion and pepper in a non-stick skillet over medium heat, until tender and starting to brown.
- To assemble each burger, stack each bun bottom with a few lettuce leaves, a mushroom cap, and some of the sautéed onion-pepper blend. Spread the underside of the bun top with some of the mashed avocado and a squirt of horseradish mustard.
Portobello mushrooms shrink when cooked, so buy the biggest caps you can find. This sandwich is best with a big, chewy mushroom hanging over the sides of the bun.
Nutrition (per serving): 307 calories, 60% calories from carbohydrates, 16% calories from protein, 24% calories from fat, 12.1g fiber.