1) Cut the zucchini into cylinders of 4-5 cm height.
2) Using a spoon, remove all the seeds and make a cup out of the zucchini cylinder. Sprinkle with salt and leave, so that all the water comes out.
3) Start the sauce by heating olive oil in a saute pan along with the butter and chuck in the garlic.
4) Add in the chopped onions and saute for 2-3 minutes.
5) Add in the tomatoes (finely chopped) along with the tomato puree.
6) Season the sauce with salt, pepper, chilli flakes and basil leaves.
7) Once cooked, blend into a fine paste/sauce.
8) Finely chop the bell peppers and toss them in the blended sauce to make a stuffing.
9) Stuff the bell pepper stuffing inside the zucchini cups and top with mozzarella cheese.
10) Bake till the cheese is melted.