Soak walnuts first if not already soaked. *You can do this by letting them sit in boiling hot water for 30 minutes or let them soak in an air tight container for up to 5 days. We usually let them sit for 24 hours and then use them. Drain soaked walnuts and put them into a food processor and pulse until you have meat like crumbles. Scrapping down as needed.*Do not over process or you will end up with walnut butter. Chop onions, garlic, and peppers.
Add a small amount of oil to a skillet, and saute onions and peppers until translucent (about 2-3 minutes).
Add in the garlic for 1 more minute.
Sprinkle garlic powder, chili powder, and smoked paprika across and stir to combine.
Add in the crumbled walnut and stir very well.
Pour in canned tomatoes, soy sauce, and liquid smoke. Stir well.
Cook until the liquid has evaporated, stirring every few minutes. This will take 20-30 minutes.
Add in the ketchup, mustard, and brown sugar. If wanting it spicy, add the sriracha.
Stir and cook until the dish is heated throughout.
Take off the stove and serve on buns