Butter a large au gratin dish. Preheat oven to 375 degrees. Bring a large pot of water to a boil over high heat; add 3 tablespoons olive oil and 1 tablespoon kosher salt. When the water boils, add the chicken breasts and return to a boil; reduce the heat so that the water just simmers, and poach breasts for 20 minutes. Off the heat, and allow the breasts to cool. Remove the meat from the hones, discard the skin, and coarsely chop the breast meat. In a large bowl, mix 2-1/2 cups of the bescamella with the mashed garlic, onions, gorgonzola and thyme; season to taste with salt and pepper. Stir in the chopped asparagus stems and the chicken meat, and mix well. Stuff each of the manicotti shells with this mixture; place an asparagus tip into one end of each manicotti. Mix the remaining bescamella with the parmesan cheese; place the stuffed manicotti in the buttered au gratin in a single layer, and spread the parmesan mixture over the top. Place the dish in the preheated oven, and bake for 20 minutes, or until heated through and the parmesan mixture is bubbling. Serve 2 manicotti per person for an entree, or 1 per person for an appetizer. pasta 7