Heat some olive oil in a big pan, add 1 diced onion and some chilli (flakes or fresh). Add 2 large diced potatoes and fry until they start looking golden. Add half of a head of cauliflower, cut up into bite sized chunks. Fry until slightly browned. Add 2 sprigs of rosemary and 3 large tomatoes, also diced. Salt to taste.
Cook pasta (any kind that the sauce will cling to - think fusilli etc).
Once the sauce has come together and the potato and cauliflower are cooked through, add a handful of chopped parmigiano (you want little chunks that will melt in the sauce and make little pockets of delicious gooey cheese) and the pasta. Stir well and enjoy!
This is also really good fried up the next day!