Slow Cooked Steak Diane Casserole is a hearty, flavorful dish perfect for a cozy dinner. Tender chunks of beef are slow-cooked in a rich, creamy Diane sauce made with mushrooms, mustard, Worcestershire sauce, and a splash of cream. This comforting casserole brings together classic steakhouse flavors in an easy, set-it-and-forget-it meal that the whole family will love.
Ingredients
For the Casserole
- 2 lbs (900 g) beef chuck or sirloin, cut into 1-inch cubes
- 2 tbsp olive oil
- 1 onion, finely chopped
- 3 cloves garlic, minced
- 8 oz (225 g) mushrooms, sliced
- 2 tbsp Dijon mustard
- 1 tbsp Worcestershire sauce
- 1 cup (240 ml) beef broth
- 1/2 cup (120 ml) heavy cream
- 2 tbsp parsley, chopped (for garnish)
- Salt and pepper to taste
For Thickening (Optional)
- 2 tbsp cornstarch mixed with 2 tbsp water
Directions
Step 1: Brown the Beef
In a large skillet, heat olive oil over medium-high heat. Add the beef cubes and sear on all sides until browned. Work in batches if necessary to avoid overcrowding the pan. Transfer the browned beef to the slow cooker.
Step 2: Sauté the Vegetables
In the same skillet, add the chopped onion and garlic. Sauté for 3-4 minutes until softened. Add the sliced mushrooms and cook for another 5 minutes until they release their moisture and begin to brown.
Step 3: Make the Sauce
Stir in the Dijon mustard and Worcestershire sauce, ensuring the vegetables are well coated. Pour in the beef broth and bring to a simmer. Season with salt and pepper.
Step 4: Slow Cook
Transfer the sauce and vegetables to the slow cooker with the beef. Stir to combine. Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the beef is tender.
Step 5: Finish with Cream
30 minutes before serving, stir in the heavy cream. If the sauce is too thin, add the cornstarch slurry and cook on high for another 20-30 minutes until the sauce thickens.
Step 6: Serve
Garnish the casserole with freshly chopped parsley and serve hot over mashed potatoes, rice, or buttered egg noodles.
Notes
- For a bolder flavor, add a splash of brandy or white wine to the sauce before slow cooking.
- You can use pre-sliced mushrooms to save time.
- This dish freezes well—store in an airtight container and freeze for up to 3 months.
Conclusion
Slow Cooked Steak Diane Casserole is the ultimate comfort food with melt-in-your-mouth beef and a creamy, flavorful sauce. Perfect for weeknight dinners or entertaining guests, this dish pairs beautifully with warm crusty bread and a side of roasted vegetables. Try it for your next family meal!
