"Green beans coated with creamy mushroom, onion and bacon sauce with the crunch of refreshing water chestnuts and delicious toasted almonds. Topped with crispy onion and bacon, baked and served golden. A beautiful addition to any meal."
Preheat oven to 275 degrees F (135 degrees C). Spread almonds on a baking sheet.
Toast almonds in the preheated oven until golden, stirring halfway through, about 13 minutes total. Remove from oven and set aside.
Increase oven temperature to 350 degrees F (175 degrees C). Grease one 9x13-inch casserole dish.
Place bacon and onion in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, 8 to 10 minutes. Remove bacon and onion with a slotted spoon; set aside. Drain excess bacon fat from the skillet; add olive oil. Add mushrooms and cook, stirring, until soft, about 5 minutes.
Place 1 quart water in a saucepan and bring to a boil. Add green beans and blanch for 2 minutes. Drain in a colander and immediately immerse in ice water for several minutes to stop the cooking process and preserve the bright green color. Drain.
Pour mushroom soup into a large bowl and whisk until smooth, adding up to 1/2 cup water, until soup is the consistency of thick gravy. Stir in almonds, 3/4 of the bacon-onion mixture (reserving the rest for topping), mushrooms, green beans, 1 cup French-fried onions, and water chestnuts. Mix thoroughly to combine and season with salt and black pepper.
Pour green bean mixture into casserole dish. Top with remaining bacon-onion mixture and 1 cup French-fried onions.
Bake in the preheated oven until bubbling and crispy on top, 30 to 45 minutes. Serve hot.