Herbed Beans and Rice

2 cans white beans
4 Tbsp. Butter
1 small onion, finely chopped
2 cloves garlic, minced
3/4 c. sliced mushrooms, optional
2 Tbsp. flour
1 can (14 1/2 oz) chicken stock
1 tsp. salt
1/4 . tsp black pepper
1/4 tsp. thyme
1/4 tsp. rosemary
1/4 tsp. oregano

Melt butter in skillet. Add onion and garlic. Add flour and cook, stirring, until slightly browned. Add remaining ingredients and simmer until thickened. Serve over rice.