Quarter, clean and chop up the capsicums. Clean celery and cut it diagonally into slices. Pare carrots and cut it into small sticks. Peal garlic and onion, cut garlic into slices and dice the onion.
Heat olive oil. Fry vegetables, onions and garlic for approximately 8-10 minutes. Wash rosemary and peel of its needles. Mash the walnuts roughly. Add rosemary, walnuts and cranberries and continue frying for 3-5 minutes. Season to taste with salt, pepper and lemon juice.
Cook the penne according tot he package insert in a lot of salt water till cooked and soft. Drain the penne and mix with the vegetable sugo.