Preheat a grill in an oven.

Place the quarters of the peppers on a baking tray (skin side up) and put under the hot grill until the skin is black and blistered (it will take about 10-15 minutes – the time depends on a grill).

When done, put the peppers to a plastic bag, seal it and leave for at least 10 minutes (this will make it easier to peel the skin off).

Heat the olive oil in a big frying pan, add the sliced onions and fry them on a medium heat for 8-10 minutes until soft and caramelised (but not burned!). Half way through add sugar and seasoning.

Cook the pasta al dente.

Peel off the peppers, cut them into slices and add to the caramelised onions together with the red beans, heat up.

Drain the pasta but save half a cup of the pasta cooking water.

Add the pasta to the frying pan, stir, check seasoning. If the dish is very dry, you may add a few tablespoons of the saved pasta cooking water.

Serve sprinkled with extra olive oil and grated Parmesan.