heat 5 tbsp olive oil in a frying pan. gently fry the artichokes, shallots/onion, garlic, parsley and mint over low heat, stirring frequently, for 10 minutes.
cook the pasta in a large pan of salted water until al dente. drain and toss well with the remaining 2 tbsp olive oil.
melt the butter in a small frying pan. add the chopped garlic and prawns and cook for a couple of minutes. (if the prawns are raw then until they go pink, if they are cooked, fry them only briefly).
add the prawns and the artichoke mixture to the pasta and mix well.