**Extra simmering won’t reliably make it milder.** Chilli’s heat comes from capsaicin, which survives ordinary cooking fairly well. Some breaks down with prolonged heating, but evaporation can concentrate the sauce and make it taste hotter. ([Research on capsaicin during cooking](https://journals.sagepub.com/doi/pdf/10.1177/1934578X1400900726))

The beans can take on the seasoned sauce, so the heat may become more evenly spread through each mouthful. They won’t neutralise it.

For your curry, **add more drained cannellini beans and tomatoes**, then simmer briefly and taste. Adding more unspiced ingredients is the most dependable fix; the [Bean Institute’s cookbook](https://beaninstitute.com/wp-content/uploads/2017/02/Northarvest_Bean_Cookbook_P2017pdf.pdf) specifically recommends extra cooked beans for an overly hot dish.

Coconut milk would also suit the curry and help soften the heat. You could serve it with plain rice and a spoonful of yoghurt, too.