For 4 servings:
Bring a large pot of water to a boil. Add a generous amount of salt. Add the squid and blanch it for about a minute. Scoop it out of the water with a large strainer and into a colander. Run the squid under cold water and then let it drain on paper towels. (Blanching firms up the squid, making it much easily to fill.) In a small bowl, combine the ricotta, egg, parsley, marjoram, Grana Padano or Parmigiano, salt, and ground black pepper. Mix everything together. Fill the squid about halfway with the ricotta mixture (using a small spoon makes this easier). Close each piece with toothpicks. Wipe any ricotta off the outside of the squid. In a large skillet, heat about 2 tablespoons of olive oil over medium-high heat. Add the stuffed squid and tentacles and the garlic cloves, and season with salt and pepper. SautÚ until the squid is golden on one side. Turn the squid to sautÚ on the other side. Add the sweet wine and the lemon peel, lower the heat, cover the skillet, and simmer until the squid is very tender, about 35 minutes, turning the pieces occasionally. When the squid is tender remove it from the skillet to a serving platter. Scatter the olives around it. Boil the skillet's cooking liquid down for about a minute, just to intensify its flavor. You want to wind up with about 1/2 cup of liquid. Pour the sauce over the squid through a fine-mesh strainer. Garnish with the whole parsley leaves. Serve hot.