Ingredients
Method
- Heat oil in a skillet over medium heat.
- Cook onion until soft, about 5 minutes.
- Add garlic and cook 30 seconds.
- Add mushrooms and cook until browned and most of their liquid has evaporated, about 6 to 8 minutes.
- Stir in walnuts, paprika, and chili flakes; cook 2 minutes.
- Add tomato sauce, ketchup, maple syrup, and soy sauce. Simmer 4 to 5 minutes.
- Season with salt and pepper, taste and adjust.
- Spoon onto buns and serve.