Grilled Portobello Mushroom Sandwich

Name: Grilled Portobello Mushroom Sandwich
Prep time: 22 min
Cook time: 8 min
Total time: 30 min
Cuisine: American
Ingredients: large portobello mushrooms, stems removed (I used 4); 2 tbsp olive oil; 3 tbsp balsamic vinegar; ½ tsp liquid smoke; 3 tbsp steak seasoning, whichever you prefer; 1 tbsp bbq sauce of choice or vegan Worcestershire (I used); 3-4 tbsp my Guinness BBQ sauce or your preferred BBQ sauce; 8 thick slices sourdough,4 burger buns or rolls; handful of greens; 2 red onions, cut into thick slices; optional toppings: pickles, horseradish; ¼ cup dairy-free butter; ¼ cup flour; 1 tbsp mustard; ⅓ cup beer (I used Guinness - FYI if you're worried about adding alcohol just know that the alcohol gets cooked out of the beer); 1 cup -1½ cup soy milk or oat milk; 1½ cups dairy-free shredded cheese; ½ tsp salt + extra to taste

Instructions

Prep:22minCook:8min

If you're craving a mouth-watering grilled portobello sandwich or burger, you're going to love this recipe! I highly recommend you also make my quick Guinness BBQ sauce for this sandwich but you can use any BBQ sauce you have at home!

Updated at: Wed, 12 Nov 2025 08:36:38 GMT