preheat oven to 375°. In a large bowl add shrimp and lobster shells. Coat with olive oil, about 1/2 cup. Roast for 20 minutes.
In a separate bowl add all chopped vegetables, 4 tbs. kosher salt and coat with 1 cup olive oil. Roast for 20 minutes.
Fold tomato paste to vegetables. Be sure all vegetables are coated then roast for another 20 minutes in oven.
In a large pot add both shrimp shells, lobster shells and roasted vegetables.
Bring to medium heat saute for 5 minutes then deglaze with white wine and cook for 10 minutes. Stirring constantly.
Next add 4 quarts water, bay leaves, thyme, tarragon, and saffron.
Reduce heat to low simmer and reduce by half. About 1 1/2 hours.
Once reduced by 1/2 in small batches add shells, broth, and vegetables to Vita-Mix blender and blend on high for 5 minutes.
Once all has been blended pass it through a chinois, fine china cap and or cheesecloth.
Make a small batch of roux (1/4 cup flour 1/2 cup melted butter). Add to medium size pot on medium heat, cook 1 minute then slowly whisk in lobster broth and 3 tbs. cognac then reduce heat to low and cook for 30 minutes.
Using a micro-fine blade or box grater fold in 2 lemons and chop 1/2 bunch fresh tarragon.
Once meat has been gently removed from shells and De-veined , place in a medium size pot and add 1 cup melted European style butter (quality), 1 shallot chopped, 1 clove garlic crushed, 5 sprigs tarragon. On low heat poach the lobster for about 5 minutes. Turn off heat and let the lobster meat sit in butter for another 3 minutes. Slice lobster tail on a bias or skewer as pictured.
In a separate bowl, whisk 1 cup heavy cream until you have whipped cream, micro fine 1/2 teaspoon nutmeg, then fold in 1 tbs. quality cognac. Serve one scoop over soup.