Creamy Chicken And Spinach Pasta

1 tsp vegetable oil
12oz boneless skinless chicken breast, cubed
1 onion, chopped
2 cloves garlic, minced
1/2 tsp pepper
2 tbsp all purpose flour
1-385ml evaporated fat free milk
5 cups whole wheat penne
half bag fresh spinach
3/4 cup diced red sweet pepper
1/3 cup shredded fresh basil
3 tbsp lemon juice
2 green onions, chopped

In large non stick skillet, heat oil over medium high heat; brown chicken. Transfer to bowl. Drain off any fat from pan. Add onion, garlic and pepper, fry over medium heat until softened, about 5 minutes. Sprinkle with flour, cook stirring for 1 minute. Return chicken and any accumulated juices to pan. Add milk; cook, stirring and without boiling, until thick enough to coat back of spoon, about 5 minutes. Meanwhile in pot of boiling salted water, cook penne until tender but firm, about 12 minutes. Add spinach; drain and return to pot. Add chicken mixture, red pepper, basil, lemon juice and green onions, toss to combine.