Add the firmer vegetables first (onion, garlic, bell pepper, chillies) to a pot with some water or oil. Add the chilli paste, mix it all together, and simmer until it all softens up a bit (but not completely).

Add passata, curry powder, and salt and pepper. Wait until it starts bubbling, then add tofu and mushrooms.

Reduce the heat and add lentils. If canned, they're already cooked, so this is just to absorb the flavour. Cook for another 3-4 minutes.