Cut one lemon in half; slice remaining lemon into quarters. Whisk flour into large pot of salted water; stir in quartered lemons. Cover and bring to a boil.

Working with one artichoke at a time, cut the stem ends from base of artichoke; peel off tough outer leaves and trim remaining leaves. Rub cut surface with lemon. Using a knife, trim around base of artichoke until rounded; rub well with lemon.

Immerse artichokes in boiling water mixture; keep submerged by weighing down with a lid slightly smaller than the diameter of the pot. Simmer for about 25 minutes or until fork-tender; drain and immerse in cold water. Drain well and, using a teaspoon, scoop out and discard choke. Place each artichoke on a plate and fan out leaves.

Mayonnaise: Meanwhile, in bowl, stand-up mixer or small food processor, beat lemon juice, egg yolk, Dijon mustard, and salt and pepper until thick. Beating constantly, add half the oil drop by drop, until very thick. Still beating, slowly drizzle in remaining oil; stir in chipotle sauce. Taste and adjust seasoning if necessary. Cover and reserve in refrigerator for up to 24 hours.

Spoon chipotle mayonnaise into the centre of each artichoke “flower” and serve.