Prepare the potatoes by peeling and slicing them thinly (about 1/8-inch thick). Place sliced potatoes in cold water to prevent browning until ready to use.
2 pounds russet potatoes
Heat olive oil or butter in a large skillet over medium heat. Add chopped onion and cook for 3-4 minutes until softened.
2 tablespoons olive oil or butter, 1 large onion
Add sliced mushrooms and cook for 5-6 minutes until they release moisture and begin to brown. If making the hamburger version, add ground beef now and cook until browned, breaking it apart. Drain excess beef fat if necessary.
8 ounces mushrooms, 1 pound lean ground beef
Add minced garlic and cook for 30 seconds until fragrant. Sprinkle flour over the mixture and stir continuously for 1-2 minutes to cook out the raw flour taste.
3 cloves garlic, 2 tablespoons all-purpose flour
Slowly add beef broth while stirring constantly to prevent lumps. Add Worcestershire sauce, dijon mustard, paprika, garlic powder, and dried thyme. Season with salt and pepper to taste.
2 cups beef broth, 1 tablespoon Worcestershire sauce, 1 teaspoon dijon mustard, 1 teaspoon paprika, 1 teaspoon garlic powder, 1/2 teaspoon dried thyme, Salt and pepper to taste
Drain the potato slices well and add them to the skillet, gently stirring to coat them in the sauce.
Bring mixture to a gentle simmer, then reduce heat to low. Cover skillet with lid and simmer for 15-20 minutes, or until potatoes are tender when pierced with a fork. Stir occasionally to prevent sticking.
Remove skillet from heat and let cool slightly for about 2 minutes. Gradually stir in the sour cream until fully incorporated and smooth. The sauce will thicken as it cools slightly.
1 cup sour cream
Taste and adjust seasonings if needed. Garnish with freshly chopped parsley before serving your homemade potato stroganoff.
2 tablespoons fresh parsley