Fill a large pot 3/4 full with water. Add 1/4 cup of the salt and bring to a boil. Rub the cut sides and bottoms of the artichokes with the lemon wedges. Squeeze the juice from the lemons into the boiling water. Add the artichokes and lemon wedges, weight with a heavy dish or bowl, and simmer, partially covered, until the bottoms are tender and can be pierced with a sharp knife and an outer leaf pulls out easily, 15 to 18 minutes. Reserve 2/3 cup of the cooking liquid for the sauce. Drain the artichokes upside down in a colander.

Cook the sausage in a medium skillet over medium-high heat, stirring, until browned, 4 to 5 minutes. Add the onions to the fat in the pan and cook, stirring, until soft, about 4 minutes. Add the garlic, oregano, and parsley, and cook, stirring, for 1 minute. Remove from the heat and let sit until cool enough to handle.

Preheat the oven to 400º F.

When the artichokes are cool enough to handle, gently press back the center leaves so the inner choke and prickly leaves are revealed. Pull out the cone of undeveloped white leaves in the center and gently scrape out the hairy choke with a spoon so as not to damage the heart.

In a large bowl combine the bread crumbs, feta cheese, 6 tablespoons of the olive oil, the water, 2 tablespoons of lemon juice, the Essence, remaining teaspoon of salt, the red pepper, and the cooled sausage mixture. Adjust the seasoning, to taste.

Gently pull the artichoke leaves outward to make space between the leaves. Fill these gaps with the sausage-bread stuffing, pushing down to pack lightly. Place the artichokes in a large baking dish and drizzle the tops with the remaining 1/4 cup of olive oil. Bake uncovered until the bread crumbs develop a nice golden brown crust, 10 to 15 minutes. Remove the artichokes from the oven and let cool slightly.

To make the sauce, in a small saucepan bring the reserved 2/3 cup of artichoke cooking liquid to a boil. In a bowl whisk together the eggs and remaining 1/4 cup of lemon juice. Whisking constantly, add about half of the hot liquid to the egg mixture in a stream, then add back to the saucepan with the remaining hot liquid. Whisk until thickened enough to coat the back of a spoon, 2 to 3 minutes, being careful not to let boil. Strain through a strainer into a clean bowl.

To serve, arrange the artichokes on a large platter or 4 individual plates. Serve with the lemon sauce on the side.