Preheat your oven to 375°F. Grease a 9x13-inch casserole dish and set aside.

In a large skillet, cook the ground beef over medium heat until browned and cooked through, breaking it up as it cooks.

Add the diced onion, green bell pepper, and minced garlic to the skillet with the ground beef.

Sauté until the vegetables are softened and fragrant. It’s not required, but add a ¼-½ cup of water to the ground beef mixture if it seems dry.

In a separate bowl, mix together the cream of mushroom soup and sour cream until well combined. Season with salt and pepper to taste.

Layer the sliced potatoes in 2 even layers on the bottom of the dish. Add more salt and pepper to taste.

Spoon the ground beef and vegetable mixture over the potatoes.

Pour the cream of mushroom soup mixture over the beef and vegetables, spreading it out evenly.

Sprinkle the shredded cheddar cheese over the casserole.

Cover the casserole dish with aluminum foil and bake in the preheated oven for 45-50 minutes, or until the potatoes are tender when pierced with a fork.

Remove the foil and sprinkle French fried onions on top of the casserole.

Continue baking for an additional 5 minutes, or until the onions are golden brown and the casserole is heated through.

Once done, remove the casserole from the oven and allow it to cool for a few minutes.

Garnish with sliced green onions or chopped fresh parsley, if desired.

Slice, serve and enjoy!