- Wash artichokes by plunging them up and down in cold water.
- Cut off stem end of each artichoke; remove bottom leaves.
- Trim about ½ inch from the top of each artichoke; trim away about one-fourth of each leaf (tip).
- Rub the top of each artichoke and trimmed edges of leaves with cut lemon to prevent discoloration.
- Arrange the artichokes, stem ends down, in a large Dutch oven; cover with water, and add the lemon juice.
- Bring to a boil cover, reduce heat, and simmer for 30 minutes or until a leaf near the center of each artichoke pulls out easily.
- Drain and set aside.
- Combine vegetable stock and oil in a nonstick skillet; place over medium heat until hot.
- Add onion and garlic; saute 3 minutes.
- Add zucchini, tomato, parsley, and bell pepper; cook 13 minutes or until tender, stirring occasionally.
- Remove from heat; stir in salt and pepper.
- Scrape out the fuzzy thistle center (choke) from each artichoke with a spoon, and discard.