In a medium bowl, combine mayonnaise, zest, juice and mustard; salt and pepper to taste. Cover and refrigerate until ready to serve
Place artichokes in a large pot of salted water, cover and bring to a boil over medium-high heat. Reduce heat to medium and cook until tender when pierced with a knife, 35 to 40 min. Drain well, Serve warm with mayo.
For a multi cooker or instant pot, add 2 cups of salted water to the pot. Insert the steamer basket and add the artichokes stem-side down. Cook on high pressure for 12 minutes and manually release the steam after the cycle is done. Small artichokes will only take 8 to 10 minutes at high pressure.
Artichokes are done cooking when the leaves pull away from the stem easily and the flesh is soft.