Put a large pot filled with water on the boil for the pasta. When it comes to rolling boil, add a generous amount of salt and the pasta, and cook very al dente.
While the water is getting ready to boil, prepare the lobster and tomato sauce:
In a sauté pan large enough to hold the lobster and pasta later on, sauté the crushed garlic in the olive oil until it just begins to brown and discard it. Add the split lobster tails and sear them on both sides, seasoning them generously with salt and pepper. As soon as the shells turn a bright red color and the meat should begin to turn an opalescent white, remove the lobster pieces from the pan. You should not cook the lobster through at this point.
Add more olive oil to the pan if needed. Add the chopped garlic and sauté until very lightly browned. Add the crushed tomatoes, a pinch of oregano and a pinch of red pepper flakes, and, if using, the clam juice or lobster broth. Simmer until the sauce is well reduced.
About 5 minutes or so before the pasta is done, add the lobster back into the sauté pan and let it simmer in the sauce until just cooked through. Remove from the pan again and keep it warm.
Fra Diavolo (Prep 2)
Once your pasta is done, drain and add it to the sauté pan, along with a good ladleful of the pasta cooking water. Let the pasta simmer in the sauce, mixing it well and making sure every strand is nicely coated with the sauce. (Add more pasta water if things get too dry—you want to the pasta to 'slither' around in the sauce.)
Pour the pasta on to a serving bowl and top with any remaining sauce in the pan and the lobster pieces.
