So..... this recipe will have more flavor if you have more shells than just the shells from the tail. Using whole lobsters or shells from whole lobster plus tails works great. Split the tails in half lengthwise with a sharp knife. De-vein the split tail. Look for the vein along the edge of the shell, between the shell and the meat. Steam the lobster tails, shell-side down in 5 cups salted water. You can use a steaming basket. Steam the tails for 5 minutes or less (do not overcook). If you are using whole lobsters, steam for 10-12 minutes. Reserve the steaming water for the stock. When cool enough to handle, remove the lobster meat from the shells. Chill the lobster meat until ready to use. In a large dutch oven, sauté lobster shells (tails, claws, legs) in 2 Tablespoons olive oil over medium-high heat , stirring with wooden spoon, for five to ten minutes to release the flavors. Deglaze the pan and scrape up the browned bits from the bottom of the pan (with shells present) with 1 cup dry white wine and 1 cup dry sherry, 3 cups stock and reserved lobster water from the steaming of the tails. Simmer until reduced to approximately 6 cups; about 30 minutes. Then strain the shells from the stock. While the stock is simmering prepare the rest of the ingredients as follows: The cup of diced tomatoes, peeled and seeded. (You can cut an X mark through the skin on the bottom of the tomato (s) with a sharp knife and then place the tomato(s) in boiling water for about 40 seconds. Remove immediately and immerse in ice water, the skin will instantly pull away. Cut the tomato in half cross wise and scoop out the seeds with your finger and then dice up. Sauté fennel and shallot in 1/4 cup unsalted butter, about 5 minutes. Stir in strained lobster stock, diced tomato, cognac, raw white rice, tomato paste, paprika, cayenne, bay leaf and thyme sprig; simmer 35-40 minutes (until rice is fully cooked and completely soft. Remove bay leaf and thyme sprig. Using an immersion blender, carefully blend the hot liquid until smooth and creamy. Stir in heavy cream and a dash of cognac to finish off the bisque. When you are ready to serve the bisque, sauté the chopped lobster meat in 2 Tablespoons unsalted butter over medium-high heat, just until warmed through and arrange in bisque. Serve immediately with crusty toasted bread.