In a stock pot, add the artichokes and lemons. Cover with water. Season the water with salt. Bring the liquid to a boil and reduce to a simmer. Submerge the artichokes in the water by lay a small cloth towel over the artichokes in the pan. Continue to cook for 12 minutes or until tender. Remove the artichokes and place in a bowl of ice water, for a couple of minutes or until chilled. Drain and pat dry.
In a mixing bowl, whisk the oil, vinegar, herbs and garlic together. Whisk until incorporated. Season with salt and pepper. Season the artichokes with salt and pepper. Toss the greens and shrimp lightly with the vinaigrette. Season with salt and pepper.
Mound a 1/4 of the greens and shrimp in the center of each artichoke.
Garnish the artichokes with the cheese, parsley, and thyme sprigs.
Yields: 4 servings