Clean and wash broccoli and cut into small florets. Dice the onion. Cook the penne in salted water until al dente. Meanwhile fry the broccoli, onions and chilli seeds (carefully dose, add the freshly chopped chilli pepper with the tomatoes) in hot oil for about 1 minute, then add the stock. Cook for about 8 minutes. The broth should be almost completely overcooked by the end of the cooking time.
Cut the sun-dried tomatoes into strips. Add tomatoes and butter and broccoli. Mix in the drained penne, arrange on plates and sprinkle with the grated parmesan.