Start by bringing a large pot of salted water to a boil. Add your egg noodles and cook according to the package instructions until they're al dente. Be sure to save about a cup of pasta water before draining — this will help thicken the sauce later and make it extra creamy!

While the noodles are cooking, heat a bit of olive oil or butter in a large skillet or Dutch oven over medium-high heat. Once it’s hot, add your beef sirloin or stew meat in a single layer. Let the beef sear without moving it for about 2-3 minutes on each side, until it's nicely browned. Searing the beef first locks in the flavor and gives it that beautiful, rich color.

Next, add the onion and garlic to the pan. Sauté for 2-3 minutes until they’re softened and fragrant. At this stage, the kitchen will start to smell incredible! If you're using mushrooms, add them now and sauté for an additional 5 minutes until they release their moisture and begin to brown.

Pour in the beef broth and bring the mixture to a simmer. Stir to scrape up any flavorful brown bits from the bottom of the pan (these add tons of flavor to the sauce). Once the broth has reduced slightly (about 5 minutes), stir in the heavy cream or sour cream. Continue to cook for another 2-3 minutes, allowing the sauce to thicken and become creamy.

Now it’s time to bring it all together. Add your cooked egg noodles to the pan with the creamy beef sauce. Toss everything together, adding a little of the reserved pasta water if needed to reach your desired consistency. The noodles should be coated in the creamy beef gravy, absorbing all that flavor.

Once everything is well combined, transfer the dish to serving bowls. Garnish with a sprinkle of fresh parsley for a pop of color and freshness. If you're feeling extra indulgent, top it off with a little grated Parmesan for that perfect finishing touch.