Preheat oven to 375°F. In large skillet melt butter and add onions until 1/2 done. Then add mushrooms, continue cooking until tender. Add cooked, shredded chicken. Salt, pepper and add garlic powder to taste. Add cheese to mixture.
Take crescents out of container, but leave them as rectangles instead of separating them into triangles. (2 triangles = one rectangle) put mixture into each one and roll it up. Place into greased pan seam side down. Whisk together milk and condensed soup, add salt & pepper. Pour over everything in baking dish.