Take 40-50 grams of fresh cilantro leaves (coriander leaves/dhaniya), 1 clove of garlic, 1 small green chili chopped, ½ inch chopped ginger. Now grind everything in a grinder and make paste. Add ¼ tsp lemon juice and pinch of salt. Mix well and keep paste aside.
In a big bowl, add 1 small finely chopped onion, ¼ chopped bell pepper (capsicum), ½ cup boiled and mashed green peas, 2 medium boiled and roughly mashed potatoes, 1 cup (130g) finely grated cottage cheese (paneer), add ¼ cup mozzarella cheese (optional) if you want you can skip adding cheese, add 1 tsp chaat masala, 1/8 tsp black pepper powder, salt to taste but not much because cheese also contains salt, 2 ½ tbsp prepared paste (cilantro, garlic, ginger, chili paste). Mix everything thoroughly. Stuffing is ready.
Take any bread slice of your choice, add 3 tbsp stuffing and spread evenly on the bread now cover stuffed bread slice with another slice of bread.
Heat tawa/pan on medium heat, you can also toast sandwich in sandwich maker. Once pan is hot place sandwich in the centre w/o butter. Gently press sandwich with spatula and leave it on pan/tawa for 2 minutes, flip after two minutes and toast sandwich for another two minutes. Sandwich is ready and crispy from both the sides. Cut it into 2 pieces diagonally (making a triangle). Serve immediately crispy sandwich with your favorite sauce/ketchup.