In a large pot, combine the artichokes and enough water to cover. Stir in half of the lemon juice. Bring to a boil and cook the artichokes until tender, about 20 minutes.
Make the vinaigrette: In a small bowl, combine the shallot, garlic, remaining lemon juice and the vinegar; season with salt. Let sit for a few minutes. Stir in the sugar, then whisk in the EVOO until emulsified. Season with the thyme, salt and lots of pepper.
Serve the artichokes with the vinaigrette for dipping.