Sauté the onions and fennel in a frying pan filled with olive oil, add the saffron and deglaze with the white wine. Cover with the cream and vegetable stock and leave to infuse for 30 minutes.

Strain the vegetables, bring the sauce to the boil and blend with the cold butter. Keep the sauce warm. Flavour the lobsters with olive oil and salt and cook gently in the oven at 100°C for 8 minutes. Cook the tagliatelle al dente and fluff them with a meat fork.

Mix the sauce with the trout roe and Osetra Imperial caviar and sprinkle over the pasta. Finish the cooked lobster tails with lime and lemon zest. Garnish optionally.