Boil water in a saucepan over medium high heat and cook the green beans for approximately 5 minutes in the water. Drain and rinse the green beans under cold water and set aside.
Cook the bacon in a large skillet over medium heat until the bacon is crispy. Move the bacon to a plate lined with paper towels and set aside.
Drain off most of the bacon grease (leave approximately 1 tbsp of grease). Add the mushrooms to the skillet and cook them over medium high heat for approximately 5 minutes until they are golden brown. Add the garlic and cook for 1 minute until the garlic is aromatic. Then remove the pan from the heat.
Crumble the bacon and add it back to the pan.
Then stir in the cream of mushroom soups, milk and salt and pepper. Then gently fold in the green beans and 2 cups of the French fried onions into the mixture.
Pour this mixture in a casserole dish.
Bake for 30 minutes, stir the mixture and then top with the remaining french fried onions.