The spaghetti is tossed with a spicy sauce studded with lobster meat. Best of all? Most of the cooking time is spent simmering.
Heat oil in a large pot over medium heat. Cook onion, garlic, and red-pepper flakes, stirring occasionally, until soft and fragrant, about 10 minutes. Add tomatoes and water. Bring to a simmer. Cook until reduced by half, about 1 1/2 hours.
Season with 1 tablespoon salt and some pepper. Add stock and lobster tails. Cook for 30 minutes. Transfer lobster tails to a plate; let cool slightly. Remove meat from shells; cut in half lengthwise. Discard shells, and return meat to sauce.
Bring a large pot of salted water to a boil. Cook spaghetti until al dente. Drain, and transfer to a platter. Stir basil into sauce, ladle over pasta, and toss.