Cut the beef into 1-inch chunks and pat dry with paper towels—this helps them brown slightly when added to the slow cooker. Dice the onion into 1/2-inch pieces, mince the garlic cloves, and thickly slice the mushrooms (thicker slices hold their texture better during the long cook). Measure out all the dry seasonings (onion powder, salt, pepper, thyme, smoked paprika) and combine them in a small bowl. I like to do all my seasoning prep at once so I can layer flavors efficiently into the broth mixture.

In a medium bowl, whisk together 1.5 cups broth, mustard, Worcestershire sauce, and the dry seasoning mixture from Step 1, stirring until the mustard is fully incorporated and the seasonings are dissolved. Add the beef, diced onion, minced garlic, mushrooms, and bay leaf to your slow cooker, then pour the braising liquid over everything, stirring gently to coat the beef. Cook on LOW for 6-8 hours (or HIGH for 4-5 hours if you're short on time). The long, gentle heat will make the beef tender and allow the flavors to meld beautifully.

About 20 minutes before the beef finishes cooking, prepare a cornstarch slurry by whisking 2 tbsp cornstarch with 1/2 cup cold broth in a small bowl until completely smooth with no lumps. This timing is crucial—adding it too early can break down the thickener, and too late means it won't fully set. Stir the slurry into the slow cooker until well combined, then let it cook for those final 20 minutes. The sauce will noticeably thicken and create a silky coating for the beef.

Remove the bay leaf from the slow cooker. Add the room-temperature cream cheese (cubed so it melts evenly) and stir until completely melted into the sauce—this usually takes 2-3 minutes of gentle stirring. Fold in the sour cream gently so the sauce stays smooth and creamy; I prefer Daisy brand for extra richness. Finish with fresh parsley for brightness. Keep the slow cooker on WARM until ready to serve, but don't let it sit more than 30 minutes or the cream cheese can start to separate.

While the stroganoff is finishing, bring a large pot of salted water to a boil and cook the egg noodles according to package directions until just tender—drain them well. Divide the noodles among bowls or plates and ladle the stroganoff generously over the top. The creamy, deeply flavored beef and mushrooms on tender noodles make for classic comfort food.