1 onion, sliced
1 cucumber, sliced
1/2 tsp. salt
4 tbsp. eggless myonnaise
2 tbsp. sriracha sauce
1 tbsp. brown sugar
1/4 cup homemade tomato puree
1 cup rajma
1 red bell pepper, finely chopped
6 cloves garlic, finely chopped
1 onion, finely chopped
200 g button mushrooms, sliced
4 burger buns