Preheat oven to 350°F and lightly grease a 9×13-inch baking dish.
In a mixing bowl, combine ground beef, crushed crackers, milk, egg, garlic powder, onion powder, Italian seasoning, salt, and pepper. Mix gently.
Shape into 6–8 oval patties.
Heat vegetable oil in a skillet and sear patties 3–4 minutes per side. Transfer to baking dish. Optional: layer thinly sliced potatoes around the patties.
In the same skillet, melt butter. Sauté mushrooms and onion until soft.
Stir in flour and cook 1 minute. Slowly whisk in beef broth. Stir until smooth.
Add heavy cream, Worcestershire sauce, thyme, and season with salt and pepper. Simmer until thickened.
Pour gravy over patties. Cover with foil and bake 30 minutes. Uncover and bake 15 minutes more.
Let rest 5 minutes, garnish with fresh parsley, and serve.
Let rest for 5 minutes, garnish with [parsley], and serve. We always scoop extra gravy, Olivia says that’s the rule.