Marinated Portobello Burgers with Caramelized Onions and Roasted Garlic Aioli

From the kitchen of One Perfect Bite...Did you ever wonder if folks who have a meat man or a fish man, also have a muffin man? I've always been slightly uncomfortable when people attach a possessive descriptor to the names of their purveyors. That makes it a bit awkward for me to talk about the person from whom I buy my mushrooms. Saturdays, rain or shine, he sells the treasures he's foraged in the wild or harvested from tunnels that he tends. This past weekend there were morels among the more common mushrooms on his table. Pure gold, and almost as expensive. Now, most mushroom hunters keep what they know to themselves. Not so this man. Save for divulging the actual coordinates of his territory, he will tell you everything he knows about foraging his favorite fungi. That's how I came to know where to look for morels in this area. Strange as it may seem, apple orchards, burned fields and the banks of streams that regularly flood are where you want to be. Using his advice I actually found one. One. Not quite enough to prepare a meal for Meatless Monday, but enough to spark a germ of recollection about a mushroom entree that would be perfect for the day. It's a burger. Strangely enough, the growers I know don't cultivate portobello mushrooms. They think they take up too much space in their limited operations. Getting back to the burgers, you'll find them very easy to make, though there may be some who object to the cost of the balsamic vinegar used to marinate the mushrooms. One thing that I want to point out is the importance of scraping away the gills of the mushrooms. If left in place, they will turn your burgers black and allow them to absorb too much vinegar. It's also important to use good, brioche-type, buns and fully ripe tomatoes. These burgers are particularly wonderful in August when ripened Brandywine tomatoes become available. Here's the recipe for a really great meatless "burger."

Marinated Portobello Burgers with Caramelized Onions and Roasted Garlic Aioli ...from the kitchen of One Perfect Bite, inspired by Cooking Light Magazine

1 cup balsamic vinegar
2 tablespoons olive oil
1 teaspoon dried basil
1/4 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
2 garlic cloves, minced
6 portobello mushroom caps
Caramelized Onions
1 tablespoon olive oil
1-1/2 cups sliced onion
1/2 cup low-fat mayonnaise
2 teaspoon bottled minced roasted garlic
Cooking Spray
6 Brioche rolls or quality hamburger buns
6 curly leaf lettuce leaves
6 large (1/3-inch thick) slices tomato

1) Combine vinegar, olive oil, basil, salt, pepper and garlic cloves in a large zip-top plastic bag. Add mushrooms. Marinate in refrigerator for 8 to 24 hours.
2) Heat oil in a medium nonstick skillet over medium-high heat. Add onion, cover and cook for 10 minutes or until golden brown, stirring frequently.
3) Combine mayonnaise and roasted garlic in a small bowl.
4) Prepare grill or broiler. Remove mushrooms from bag, discarding marinade. Place mushroom caps on grill rack or broiler pan coated with cooking spray; cook 5 minutes or until tender.
5) Lightly toast buns. Spread top and bottom of each bun with aioli. Place a lettuce leaf on bottom half of each bun, top with a tomato slice, a mushroom cap, 1 tablespoon caramelized onion and top half of bun. Serve immediately. Yield: 6 servings.

You might also enjoy these recipes:
Baked Portobello Parmesan - One Perfect Bite
Mushroom Lasagna Florentine - One Perfect Bite
Wild Mushroom Ragu - One Perfect Bite

This recipe is being linked to Meatless Monday at My Sweet and Savory