In a large pot over medium heat, melt the grass-fed butter.
Add the diced onion, celery, and carrot to the pot, sautéing for 5-7 minutes until the vegetables are soft and translucent.
Stir in the tomato paste and fresh thyme, cooking for another 2 minutes to deepen the flavor profile.
Pour in the dry sherry to deglaze the pan, scraping up any browned bits from the bottom.
Add the seafood stock, sea salt, and black pepper, bringing the mixture to a gentle simmer for 15 minutes.
Using an immersion blender, carefully blend the soup base until it is completely smooth and velvety.
Stir in the heavy cream and the cooked lobster meat, heating through for 3-4 minutes until the lobster is warm.
Ladle the bisque into a bowl and garnish with freshly minced chives before serving.