Amazing Veggie Burgers with Mushrooms

15 oz can kidney beans, drained and rinsed
1 small red onion, shredded and squeezed dry
1/3 cup chopped walnuts
1 small carrot, finely diced
1 cup plain breadcrumbs
2 scallions, finely chopped
2 Tbsp chopped parsley
2 Tbsp Worcestershire or soy sauce
kosher salt and fresh ground pepper
3 Tbsp olive oil
3 cups mushrooms, sliced
4 english muffins, toasted
garnish: mayo, mustard, baby spinach, sprouts

Smash the beans in a bowl with a fork until chunky. Add onions, walnuts, carrot, 1/2 cup breadcrumbs, scallions, parsley 1 tsp sauce. Season with salt and pepper and mix with hands. Form mixture into 4 patties. Lightly coat with remaining 1/2 cup breadcrumbs. Heat 2 Tbsp oil in skillet over medium-high heat and cook patties till golden, 2-3 minutes per side. Heat 1 Tbsp oil over medium heat, add mushrooms + 1 tsp sauce. Season with salt and pepper and cook 3-4 minutes. Serve on english muffins with your choice of garnish.