Steam or boil lobsters until just tender, 8 to 10 minutes.

Cool, then remove all lobster meat from shells. Refrigerate meat, covered; set aside.

In large saucepan, heat 2 tablespoons clarified butter. Add onion, carrot, celery, garlic, thyme, tarragon, and bay leaf; toss over high heat 3 minutes.

Add lobster shells, stirring; then add 2 tablespoons Cognac and stir for 3 minutes.

Add butter and tomato paste and simmer gently, covered, 2 to 3 hours.

Strain, pressing solids firmly. Set aside for 15 minutes.

Skim any froth from surface and strain again through several layers of dampened cheesecloth, leaving behind any milky residue in bottom of pan (discard residue.) Cool, then chill or freeze in small containers.

Chef: Stanley Kramer, Oyster Bar and Restaurant,