FOR THE SAUCE
Heat olive oil in a medium saucepan. Add garlic and red pepper or pepper flakes, and cook until garlic is slightly browned (do not burn it).
Add and stir in the tomatoes, fresh herbs and salt. Add lobster or clam stock. Simmer until thickened, about 30 minutes. During the last five minutes, prepare and cook the lobsters.
FOR THE LOBSTERS
If you are timid about killing a lobster, have your fishmonger do it for you.
Melt the butter in a large, deep skillet. Add olive oil and turn up the heat to very high. At this point, everything should be done very quickly. Add the lobsters in the shell, and sear them on all sides. Pour on the cognac to ignite.
Add the wine and the sauce, reduce the heat, and cover. Simmer for 20 minutes. Serve with a large slice of polenta.