Casserole Steak Recipe

Marinate steak

Finely mince the garlic. In a bowl combine soy sauce, Worcestershire sauce, 1 tablespoon olive oil, minced garlic, 1/2 teaspoon salt and 1 teaspoon black pepper. Trim excess fat from the steak and place the steak in a shallow dish or resealable bag. Pour the marinade over the steak, turn to coat, and refrigerate for 30 minutes (or up to 2 hours) while you prepare the other components.

Sear steak

Preheat oven to 375°F (190°C). Heat a large ovenproof skillet over medium-high heat and add 1 tablespoon olive oil. Remove steak from marinade and pat dry with paper towels (reserve marinade). Sear steak 2–3 minutes per side until browned. Transfer steak to a cutting board and let rest 5 minutes, then cut into 1-inch cubes. Keep skillet with fond for the casserole base.

Prepare vegetables

While steak marinates and rests, peel and cut potatoes into 1/2-inch slices or halve baby potatoes. Peel and slice carrots into 1/4-inch rounds. Slice onion thinly. Trim and slice mushrooms if large.

Cook vegetables

In the same ovenproof skillet used to sear the steak, add 2 tablespoons butter and 1 tablespoon olive oil over medium heat. Add onions and carrots and cook 5 minutes until starting to soften. Add mushrooms and cook 3–4 minutes until they release moisture. Stir in 2 tablespoons flour and cook 1 minute to remove raw taste.

Build sauce

Slowly whisk in the reserved marinade (if any) and 1 cup beef broth, scraping browned bits from the skillet. Add 1 tablespoon tomato paste, 1/2 teaspoon dried thyme, 1/2 teaspoon dried rosemary, 1 bay leaf, 3/4 teaspoon salt and 1/2 teaspoon black pepper. Bring to a simmer and cook 3–4 minutes until slightly thickened. Taste and adjust seasoning. Stir in 1/2 cup frozen peas.

Combine steak and vegetables

Add the cubed steak back to the skillet and gently fold to coat in the sauce. If your skillet is too small, transfer mixture to a 9x9-inch (or similar) casserole dish. Arrange halved baby potatoes (or potato slices) on and around the meat mixture so they can roast in the sauce.

Prepare potato topping

If using prepared mashed potatoes: combine 2 cups mashed potatoes with 1/4 cup milk, 1 tablespoon butter, 1/4 teaspoon salt and 1/4 teaspoon black pepper until smooth. If using leftover mashed potatoes, adjust milk for desired consistency. If using instant flakes, prepare according to package to equal 2 cups.

Assemble casserole

Spoon or pipe the mashed potato mixture over the meat and vegetable filling in an even layer, covering the surface. Sprinkle 1 cup shredded cheddar evenly over the mashed potatoes.

Bake

Bake in the preheated 375°F (190°C) oven for 20–25 minutes until the filling is bubbling at the edges and the cheese is melted and lightly golden. If you want a browner top, place under the broiler 1–2 minutes, watching closely.

Rest and serve

Remove from oven and let rest 5 minutes. Remove bay leaf before serving. Spoon portions onto plates and serve warm.