Step 1: Heat the extra virgin olive oil in a large Dutch oven or heavy pot over medium heat. Add the diced onion, minced celery, and minced garlic. Sauté for 5 to 7 minutes, stirring occasionally, until the vegetables are soft and translucent.
Step 2: Add the tomato paste, smoked paprika, and fresh thyme to the pot. Cook for an additional 2 minutes, stirring constantly, until the paste turns a deep red color and smells fragrant.
Step 3: Slowly pour in the seafood stock, using a wooden spoon to scrape up any browned bits stuck to the bottom of the pot. Bring to a gentle boil, then reduce heat to low and simmer uncovered for 10 minutes.
Step 4: Gently stir in the raw shrimp and cook for 3 to 4 minutes until they turn pink and opaque. Add the crab meat and stir gently for 2 minutes to warm it through.
Step 5: Optional for texture: If you prefer a smoother bisque, remove half of the seafood with a slotted spoon and set aside. Use an immersion blender to partially purée the remaining soup until creamy and smooth. Stir the reserved seafood back into the pot.
Step 6: Reduce heat to low. Slowly stir in the heavy cream (or Greek yogurt). Let the soup warm through for 1 minute without letting it boil. Remove from heat, stir in the fresh parsley and optional lemon juice. Season with salt and pepper to taste, and serve immediately.