These marinated portobello mushroom burgers are the perfect, hearty main dish for all your summer parties. They are surprisingly easy to make and delight both meat and plant eaters!
Prepare marinade by whisking all ingredients together in a bowl.
Prepare mushrooms by wiping mushroom tops clean with a damp cloth. Remove stems. Place in a shallow dish with the stem side facing up. Pour the marinade evenly over the mushrooms. Cover and allow to marinate at least 30 minutes or overnight.
Remove mushrooms from marinade. Reserve marinade for basting. If planning to grill red onions for topping, brush the slices with a little olive oil. Grill mushrooms and onions for 5-7 minutes per side, basting periodically with the reserved marinade. Transfer to a clean plate. The mushrooms will release liquid during and after grilling, so it's best to leave them stem side down after grilling.
Assemble the mushroom burgers with toppings and serve immediately.
Notes
Nutrition facts include serving on a gluten-free bun.
Tamari is a gluten-free soy sauce. For a soy-free option, use coconut aminos.
The longer you marinate the portobello mushrooms, the more flavorful they will be. If you have time, start marinating the night before you want to grill.