The Best Grilled Portobello Mushroom Burgers

I go back and forth about portobello burgers.  My biggest issue with portobello burgers is how slimy they can be sometimes.  I hate that.  I decided to give these a go and hope for the best.  They really were great.  I adapted this recipe from SkinnyTaste.


4 portobello mushroom caps
2 tbsp balsamic vinegar
1 tbsp low sodium soy sauce
1 tbsp olive oil
1-1/2 tsp Montreal Steak Grill Mates seasoning
4 thick slices red onion
4 slices Swiss Cheese
4 thin slices tomato
1 sliced avocado
4 hamburger buns

Wash the portobello caps, remove the stem and the black flesh from the bottom.  Mix together the balsamic vinegar, soy sauce, olive oil and montreal steak grill mates seasoning.  Whisk it together well then brush the marinade over the portobellos.  Brush several times while letting the portobellos sit for 30 minutes.  Heat the grill to medium heat and grill the mushrooms for 5 to 7 minutes on each side.  Top with swiss cheese and remove from grill.  Top with onion, tomato and avocado then serve on a toasted bun.