Wipe the Portobello mushrooms clean with a damp cloth and remove the stems. Finely chop the mushroom caps into small pieces.
Sauté the Aromatics:
Heat olive oil in a large skillet over medium heat. Add the diced onion and bell pepper. Sauté for 3-4 minutes until softened.
Stir in the minced garlic and cook for an additional 30 seconds until fragrant.
Cook the Mushrooms:
Add the chopped Portobello mushrooms to the skillet. Cook for 5-7 minutes, stirring occasionally, until the mushrooms release their liquid and begin to brown.
Make the Sloppy Joe Sauce:
Stir in the tomato sauce, tomato paste, soy sauce, maple syrup, smoked paprika, chili powder (if using), salt, and black pepper. Mix well to coat the mushrooms evenly.
Reduce the heat to low and simmer for 5-7 minutes, allowing the flavors to meld and the sauce to thicken slightly.
Assemble the Sloppy Joes:
Toast the hamburger buns if desired. Spoon the mushroom mixture generously onto the bottom half of each bun.
Add your favorite toppings like pickles, coleslaw, or vegan cheese slices, then place the top bun on each sandwich.
Serve:
Serve warm with a side of fries, sweet potato wedges, or a crisp green salad.
Serving and Storage Tips:
