Melt butter on medium-high heat in a large skillet. Then add in the green beans, diced white mushrooms, dried minced onions, water, salt, pepper, Better Than Bouillon mushroom base. Mix well. Place a lid on the skillet. Cook on medium-high heat for 10 minutes until green beans are just slightly cooked.
While green beans cook. Mix together the cornstarch and water until fully combined. Set to the side.
Preheat the broiler on high.
Once the green beans are done cooking. Turn the heat off, and stir in the heavy cream. Then, stir in the corn starch slurry. Mix until thick.
Transfer to an oven proof dish. Pour the green beans in the dish. Top with the French Fried Onions.
Broil on high for 1-2 minutes or until the onions are golden in color (but not burnt). Serve immediately