Wash the asparagus, peel the lower third and cut off the ends. Cut the asparagus diagonally into pieces. Bring the stock to the boil, cover the asparagus and cook for 6-8 minutes. Meanwhile drain artichoke hearts and cut into slices.
Peel onion and garlic. Chop the onion finely, press the garlic through a garlic press. Heat olive oil in a pot, fry onion and garlic until transparent. Stir in tomato paste, add asparagus, stock and chunky tomatoes.
Season with salt, pepper and oregano and simmer for 5-10 minutes. Meanwhile cook the pasta in plenty of boiling salted water for 10-12 minutes and drain. Add the artichokes to the hot sauce and warm them up briefly.
Mix penne and sauce and arrange on plates. Serve garnished with parsley.