Finely dice the yellow onion, celery, and carrots to create a uniform mirepoix.
Melt the ghee in a large heavy-bottomed pot over medium heat.
Add the diced vegetables to the pot and sauté for 5-7 minutes until they are softened and translucent.
Stir in the tomato paste and cook for 1 minute, allowing it to caramelize slightly and deepen in color.
Carefully pour in the dry sherry to deglaze the pan, using a wooden spoon to scrape up any flavorful browned bits from the bottom.
Add the seafood stock and fresh thyme sprigs, then bring the mixture to a gentle simmer for 15 minutes.
Remove the thyme sprigs and use an immersion blender to process the soup until it is completely smooth and velvety.
Whisk in the full-fat coconut milk and season with sea salt and black pepper.
Gently fold in the lobster meat and simmer for an additional 3-5 minutes until the lobster is heated through.
Ladle the bisque into bowls and garnish with finely chopped fresh chives before serving.