In a large pot over medium heat, soften the onion, celery, garlic and ginger in the butter. Add the spices and continue cooking for 1 minute. Add the tomato paste and stir to coat. Add the broth and lentils. Season with salt and pepper. Bring to a boil, then simmer for 10 minutes.
Add the cauliflower and continue cooking for 5 minutes over medium-high heat. Add the shrimp and pasta and cook for 2 more minutes. Remove from the heat and let rest for 5 minutes before serving.
Add the cilantro. Divide the soup among six bowls. Garnish with the sour cream and serve with lime wedges.
Recipes with the "Healthy Pick" stamp have been evaluated by a registered dietitian member of the Ordre professionnel des diététistes du Québec.