Set the Instant Pot to sauté mode. Spray the base with vegetable cooking spray. Heat the olive oil and sauté the diced onion, carrots, and celery until softened, about 5-7 minutes.
Add the minced garlic, paprika, cayenne pepper, and dried thyme. Sauté for an additional 1-2 minutes until fragrant.
Add the peeled and deveined shrimp (reserving a few for garnish) to the pot. Cook for 2-3 minutes until they start to turn pink.
Stir in the diced tomatoes, pimentos (reserving some for garnish), and bay leaves. Mix well.
Pour in the chicken or vegetable broth. Cancel sauté mode and secure the Instant Pot lid. Cook on high pressure for 5 minutes, then perform a quick pressure release.
Remove the bay leaves and use an immersion blender to blend the soup until smooth. Or transfer the soup to a blender in batches, blend, and return it to the Instant Pot.
Set the Instant Pot back to sauté mode. Stir in the fat-free half and half and let the bisque simmer for an additional 5-7 minutes. Season with salt and pepper to taste.
Serve the creamy shrimp bisque hot, garnished with reserved large shrimp, chopped fresh parsley, and a sprinkle of reserved pimentos.
This makes 6 large servings at about 1.5 cups per serving. On Weight Watchers, each serving is 3 WW Points. Enjoy!