Squeeze the excess oil out of the sun-dried tomatoes, then thinly slice. Place in bowl with chickpeas.
In the other bowl, combine 4 c water with 2 T lemon juice. Prepare the artichokes by pulling off the tough outer leaves, and continue until you reach the tender yellow or pale green leaves inside (you can save the removed leaves to eat the normal way). Cut off the dark green top of the artichoke and all but an inch of the stem. Trim the stem and smooth any rough areas with a knife.
- If using baby artichokes, cut into pieces and place in water.
- If using large artichokes, cut one in half lengthwise and place half in the water. Cut the inner purple leaves and hair off the other half, then cut the artichoke into pieces.
Repeat with remaining artichokes, placing each finished piece in the water.
Add remaining 2 T of lemon juice to a pot of water and bring to boil. Add artichoke pieces and boil until just tender, 3-4 minutes. Drain.
Over medium-low heat, warm 1 T olive oil in frying pan. Add onions, garlic, and celery and sauté, stirring occasionally, until onions begin to color, about 10 minutes. Stir into chickpeas.
Heat remaining 2 T olive oil. Without stirring, sauté the artichokes over medium heat until brown. Flip and brown the other side, then add to the chickpeas.
Drizzle with vinaigrette and mix well. Let sit for a few minutes.
Serve warm on a bed of mesclun.