In a saucepan, sauté the garlic, onions, chili and celery in the olive oil for about 5 minutes. Add the tomato pieces, paprika powder and cumin and simmer over medium heat for another 5 minutes, stirring frequently. Add corn, basil, tomato juice and broth and bring to the boil, then reduce the heat and let it steep for another 15 minutes. At the end, add the lime juice and the avocado cubes. Break some nachos and place in each plate, add the soup and put a teaspoon of creme fraiche or sour cream in the middle and sprinkle with basil. Serve immediately.