Soba Noodle Soup with Beef

Name: Soba Noodle Soup with Beef
Ingredients: 1 tsp. oil; 8 oz. beef sirloin; 2 can fat-free chicken broth; 2 c. water; 1 red bell pepper, quartered; ¾ c. sliced carrot; 3 tbsp. light soy sauce; 2 tsp. each minced garlic and grated fresh ginger; 8 oz. uncooked soba noodles; 1 small bunch bok choy (about 12 oz); ½ c. each sliced scallions and chopped cilantro