- Shell the lobsters. Chop the lobster meat and refrigerate.
- Place the lobster shells in a large pot. Using a kitchen mallet, break the shells into smaller pieces.
- Add the butter and cook the lobster shells over medium-high heat for 5 minutes, stirring to coat them well in the butter. Add the shallots, tomato paste, garlic and bay leaf. Cook until the shells start to brown, about 5 minutes.
- Deglaze with the brandy. Add the white wine and let reduce by half. Add the cream and simmer for 10 minutes.
- Meanwhile, in a large pot of salted boiling water, cook the pasta until al dente. Reserve ½ cup (125 ml) of pasta cooking water. Drain the pasta.
- Strain the sauce through a very fine sieve set over a skillet. Compost the lobster shells. Season the sauce with salt and pepper.
- Add the pasta and lobster meat to the sauce. Reheat for 2 minutes, stirring to coat everything well in the sauce. Adjust the seasoning. Add some of the reserved pasta cooking water as needed if the sauce is too thick. Serve the pasta in bowls. Sprinkle with chives or tarragon, if desired.