2 large garlic (cloves, minced)
2 tablespoons thyme (fresh)
1 cup cannellini beans (cooked or canned, drained and rinsed )
2 tablespoons olive oil
1 teaspoon black pepper
8 large portobella mushroom (caps, stems trimmed)
4 teaspoons balsamic vinegar
2 large onion (red, peeled and cut into thin rings)
4 large hamburger buns (whole-grain)
2 ounces cheddar cheese (thinly sliced, 4 equal portions)
1/2 ounce arugula (rinsed well and dried)
1 ounce Nonstick cooking spray (for onions)