1/2 cup finely chopped red bell pepper
1 clove garlic, minced
1/4 cup olive oil
1/4 teaspoon onion powder
1 teaspoon salt
1/2 teaspoon ground black pepper
4 portobello mushroom caps

Preheat grill for medium heat.
In a large bowl, mix the red bell pepper, garlic, oil, onion powder, salt, and ground black pepper. Spread mixture over gill side of the mushroom caps.
Lightly oil the grill grate. Place mushrooms over indirect heat, cover, and cook for 15 to 20 minutes.