In a blender, add the tomatoes, chicken broth, onion, garlic, chiles, and salt, and blend until smooth. Heat 2 tablespoons oil in a 4-quart non-stick saucepan, over medium-high heat. Add the pasta and cook, stirring constantly, for about 2 to 4 minutes, or until pasta is golden brown. Strain the blended tomato mixture over the pasta using a strainer. Cover and cook over medium-low heat for 10-14 minutes, or until the pasta is tender. Pour the soup into bowls and dollop with sour cream. Garnish as desired and serve. Tip: thin spaghetti pasta may be used in place of fideo pasta.