Pulse pasta ingredients in a food processor until breadcrumb texture forms.
Knead dough on a floured surface for 5 minutes, wrap in film, and chill for 15 minutes.
Feed halved dough through a pasta machine, decreasing thickness settings gradually until thin.
Trim edges of two equal pasta rectangles and set aside on a floured tray.
Blend lobster claws and one tail into a paste, then chill for 10 minutes.
Blend 100ml cream and stock into the lobster paste until smooth.
Mix in tarragon, eggs, cayenne, and lemon; transfer to a piping bag and chill.
Pipe four mounds of filling on one pasta sheet and top each with reserved tail meat.
Moisten pasta edges with water leaving a 3cm gap around filling.
Top with the second pasta sheet, cut into four ravioli, and seal edges carefully.
Boil ravioli for 3-5 minutes until al dente then remove with a slotted spoon.
Sauté lobster shells in butter and oil, add vegetables and garlic, then stir in tomato purée.
Deglaze with brandy, add chicken stock, and reduce liquid by half.
Strain sauce, discard solids, bring to a boil, and stir in 150ml cream.
Serve one raviolo per bowl topped with lobster cream sauce.