Firstly, in a large pan, heat 1 tbsp oil and add 1 small chopped onion.
Cook for 1-2 minutes and keep the flame at medium.
Add ½ chopped capsicum and mix well. Cook for 1 minute.
Add 1 cup chopped mushrooms and cook for 1-2 minutes.
Don’t cook it too soft, and try to maintain its crunch.
Add 1 tsp each chilli flakes, oregano, pizza pasta sauce, and white mayonnaise, and give it a good mix.
After being perfectly cooked, turn off the flame.
Take 4 bread slices out of which take 1 bread slice and spread the prepared mixture over it.
Cover it with another bread slice and similarly prepare the other one.
Heat a tawa and spread oil over it. Place the bread sandwich and apply oil on top.
Flip it and roast both sides until golden brown.
After being perfectly roasted, remove it from the tawa and similarly, prepare the other sandwich.
Cut it from the centre to form the triangles.
Finally, enjoy mushroom sandwich with tomato ketchup.