Ths portobello mushroom burger recipe has a nice combination of flavors.
Marinade the mushroom caps first.
In a seal type bag, combine the oil, vinegar, rosemay and lemon juice. Put the mushrooms into the bag, seal it and turn the bag over and over a few times to coat the mushrooms. Let them marinate for 15 minutes.
Heat a skillet on the stovetop with a tablespoon of oil. Or, you can cook on an outside grill.
Place the mushrooms, cap side down and cook for 6 minutes. Flip to cap side up and cook another 6 minutes.
Season the mushrooms on each side as they are cooking with salt and pepper. Place the feta cheese onto the mushroom caps. Cover the skillet with a lid so you heat the cheese a little, cooking one minute longer.
Red Pepper Paste
In a blender, Combine 2/3rds of the jar of roasted red peppers, with the oil, parsley, and garlic. Pulse to make a thick sauce.
Toast the buns. Butter the buns if you like.
Spread the red pepper paste onto the bottoms. Place a layer of greens, followed a mushroom with cheese, the reserved roasted pepper and top with a bun.