For the lobster broth: Heat a large soup pot on medium and add the butter, olive oil, garlic, carrots, celery and onions. Add the sea salt and some freshly cracked pepper and saute for about 8 minutes. Deglaze the pan with the brandy and burn off the alcohol. Pour in the white wine and reduce for 1 to 2 minutes. Add the vegetable stock, tomato paste, peppercorns, lobster carcasses (keep meat for later), bay leaves, parsley and thyme. Top of with water, just enough to cover the shells. Turn the heat down to medium-low and simmer, partially covered, for 1 hour.
For the dark roux: Heat a small saucepan on medium. Add the butter and flour and whisk continuously until amber in color and nutty smelling, 6 to 7 minutes. Remove from the heat. For the bisque: Using strainer and cheesecloth, strain the lobster broth into a medium pot. Add the dark roux, heavy cream and saffron and mix. Let reduce on medium-low heat until thick, another 15 to 20 minutes.
For the lobster meat: Heat a big pan on medium-high and melt the butter. Add the lobster meat and saute until heated through, 1 to 2 minutes. Spoon the lobster meat into a big bowl, ladle on the lobster bisque and top with chives.