Tote this easy-to-make soup off to lunch and don't forget the crackers.
In a small saucepan, bring reduced-sodium chicken broth and 1/4 cup water to a boil. Add minced garlic clove, egg noodles, and green beans, cut crosswise into 1-inch pieces (1/2 cup). Reduce heat; simmer 5 minutes.
Add grated carrot and skinless, boneless chicken breast, cut into 1/2 -inch pieces (1 cup); simmer until chicken is cooked through, about 3 minutes. Remove from heat; stir in 1 thinly sliced scallion. Season with coarse salt and ground pepper.
To store this soup, cool completely; refrigerate in an airtight container up to overnight. Reheat over low heat or in microwave.