Cut kumara into 1 cm(½ in) cubes and place in a deep saucepan. Cover with cold water, add some salt and cook until almost tender. Meanwhile, bring a saucepan of salted water to the boil and cook pasta until al dente. Just before kumara is ready, add peas to the pan and continue to cook until they’re done. Drain in a colander and tip into a large bowl. Drain pasta and add to bowl.
Sauté chillies and garlic in oil in a small frying pan until coloured. Remove from heat, stir in mint, then pour over pasta and gently toss. Serve dredged with parmesan and black pepper.