1. In a skillet, heat 2 tablespoons of oil over medium-high heat. Season the beef blade steaks with salt and pepper to taste. Place the steaks in the skillet and brown them on both sides, working in batches if necessary. Transfer the browned steaks to the slow cooker. (Browning step is what gives the meat extra flavor.)
2. In the same skillet, add the remaining 2 tablespoons of oil and sauté the sliced mushrooms and onions until they are tender and slightly browned. This should take about 5 minutes.
3. Add the minced fresh thyme and sweet paprika to the skillet and stir them into the mushroom and onion mixture. Cook for an additional minute to enhance the flavors.
4. Transfer the mushroom and onion mixture to the slow cooker, spreading it evenly over the beef steaks.
5. In a separate bowl, whisk together the chicken stock, dry sherry, and flour until well combined and no lumps remain. Pour this mixture over the beef and mushroom mixture in the slow cooker.
6. Cover the slow cooker and cook on low heat for 6-8 hours (or high for 4-5), or until the beef is tender and cooked through.
7. Once the cooking time is complete, carefully remove the beef steaks from the slow cooker and set them aside.
8. Stir in the chopped fresh parsley and cream into the sauce in the slow cooker. Mix well to combine. Return the beef steaks to the slow cooker, coating them with the creamy mushroom sauce.
9. Cover the slow cooker again and let it cook on low heat for an additional 10 minutes, allowing the flavors to meld together.
Serve the slow cooker Swiss steak with mushrooms over a bed of cooked rice, mashed potatoes, or alongside your favorite side dishes. Enjoy!