Chicken and Orzo Skillet Dinner

I actually used pork tenderloin when I made this, but chicken would be good, too!

INGREDIENTS:
1 pound skinless, boneless chicken breast halves, cut into bite sized pieces
8 cups water
12 oz uncooked orzo
2 cups chopped tomato
2 tsp no-salt-added tomato paste
1/2 tsp salt
1/2 tsp crushed red pepper
1/4 tsp black pepper
3 cups baby spinach leaves
3 ounces feta cheese, crumbled

DIRECTIONS:
Heat a nonstick skillet over med-high heat. Add chicken and saute 6 minutes, turning to brown on all sides. Remove chicken from pan; keep warm. Bring 8 cups of water to boil in a large saucepan. Add orzo; cook 8 minutes or until orzo is al dente. Drain in a colander over a bowl, reserving 1/4 cup cooking liquid. Add reserved cooking liquid, chopped tomato, tomato paste, 1/2 tsp salt, and peppers to skillet; cook over med-high heat for 2 minutes. Add chicken, pasta, and 3 cups of spinach leaves, stirring until spinach wilts. Remove from heat; sprinkle with cheese.