Chicken Corn Chowder

1 Tbsp margarine or butter

1 (8 oz) pkg sliced mushrooms

1/4 C flour

3 1/2 C 2 % milk

1 C chopped red potato

1/2 tsp dried thyme

1/2 tsp salt

1/4 tsp pepper

1 (16 oz) pkg frozen corn, thawed

1 1/2 C shredded cooked chicken breast

3 Tbsp chopped green onions, divided

Melt margarine in a large Dutch oven over medium-high heat.  Add the mushrooms, and saute for 3 minutes.  Stir in the flour.  Gradually add the milk, stirring with a whisk.  Add the potato, thyme, salt, pepper and corn.  Bring to a boil.  Stir in the shredded chicken and 2 Tbsp green onions.  Cover, reduce heat and simmer for 5 minutes.  Ladle the soup into bowls, and sprinkle with remaining green onions.