Peel and dice the carrots and potatoes. Wash leeks and cut into rings. Peel and chop onion and garlic. Heat oil over medium heat and sauté onion for 3 minutes. Add carrots, leeks and garlic and sauté all 10 minutes, stirring often. Add the soup, simmer for 20 minutes. Pour in cream, bring to the boil and continue to simmer for five minutes. Puree with a hand blender and season with salt and pepper. Rinse shrimps cold, drain and set when serving in the middle of the soup.