Season the cubed steak with salt and pepper. In a large skillet, heat olive oil over medium-high heat. Add the steak and brown on all sides, about 5-7 minutes. Transfer the browned steak to the slow cooker.
In the same skillet, add diced onion and minced garlic. Sauté until the onion is translucent, about 3-4 minutes. Add this mixture to the slow cooker.
Layer the sliced potatoes over the steak and onion mixture.
In a bowl, combine beef broth, Worcestershire sauce, thyme, and paprika. Pour this mixture over the potatoes in the slow cooker.
Cover and cook on low for 6-8 hours or on high for 3-4 hours, until the potatoes are tender and the steak is cooked through.
About 30 minutes before serving, sprinkle the shredded cheddar cheese on top and cover to allow it to melt.
Before serving, stir in the sour cream for added creaminess.