Creamy Chicken Pasta Soup

This recipe is from Jeanene Davey, who is a fantastic cook.

3 T butter
4 oz. button mushrooms (sliced)
1 cup celery (Bob thinks these are optional!)
1 cup shredded carrots
3 T flour
6 cups chicken stock
1.5 cups half and half
2 T parsley
1.5 pounds chicken breasts, cooked and cut up
1 cup penne pasta
1/4 cup sugar snap peas, halved (or you can use green peas)
3 T lemon juice

Cook penne pasta according to package directions and set aside (10 minutes or so). Melt butter in pot, add mushrooms, celery, carrots and onion. Cook until tender (5 minutes). Add flour and cook 3 minutes, stirring frequently. Add half & half and parsley. Simmer for 5 minutes. Add chicken, simmer another 5 minutes. Mix in cooked pasta and peas. Mix in lemon juice, and season with salt and pepper. Total time 25 (provided that you have pre-cooked chicken!)