Method
Preheat oven to 400 degrees F. Brush portobello mushrooms with olive oil and season with salt and pepper. Place on a sheet pan, stem side up, and roast in oven for 15 minutes. Turn mushroom caps over and roast an additional 5 minutes, until vinegar has reduced to about 2 tablespoons and is syrupy. Set aside.
Remove mushrooms from oven, turn again, and fill cavity with crumbled jalapeno feta. Return to oven and bake just until cheese melts, about 3 minutes. Cool slightly and quarter each mushroom. Brush baguette slices with olive oil and toast until golden brown. Place mushroom on toasted baguette, sprinkle with red pepper, and drizzle with reduced vinegar. Garnish with cilantro.
Photo and Recipe Courtesy of Whole Foods Market.