In a medium pot over medium heat, melt the grass-fed butter until it begins to foam.
Add the diced onion, celery, and carrot, sautéing for 5-7 minutes until the vegetables are softened and translucent.
Stir in the garlic and tomato paste, cooking for 2 minutes to caramelize the paste and release the garlic's aroma.
Pour in the dry sherry to deglaze the pot, scraping up any browned bits from the bottom with a wooden spoon.
Add the seafood stock, sea salt, and black pepper, bringing the mixture to a gentle boil before reducing heat to low and simmering for 15 minutes.
Using an immersion blender, carefully puree the soup until completely smooth and velvety.
Stir in the heavy cream and the lobster meat, heating through for 3-4 minutes until the lobster is tender and warm.
Ladle the bisque into a bowl and garnish with freshly chopped chives before serving.