Place the lentils in a pot with hot salted water until they are covered by around 1cm and bring to a boil. Let simmer until the lentils are cooked through, around 30 mins.
In a bit pot on medium heat, add the olive oil and the onion. After around 3 minutes, start adding the rest of the ingredients gradually starting with the carrots, peppers, peas and garlic.
Once the vegetables are softened, add the crushed tomatoes and tomato paste. Add the cooked lentils to the pot. If the sauce is too thick, add a bit of water until it’s runny (you can use any leftover water from the lentils).
Bring to a boil and then simmer until the sauce is thickened, around 15 minutes. Add the 7-spice, chilli and salt and taste to adjust the seasoning.
Serve with spaguetti or other pasta that you like.