1. Preheat your oven to 350°F (175°C) to get it ready for baking later.
2. Bring a large pot of salted water to a boil. Add the egg noodles and cook until just al dente, about 6-7 minutes. Drain and set aside.
3. While the pasta cooks, heat the olive oil and butter together in a large skillet over medium heat. Add the chopped onion and sauté until translucent and fragrant, about 4 minutes.
4. Add the garlic and mushrooms, cooking until the mushrooms release their moisture and begin to brown, another 5 minutes.
5. Increase the heat to medium-high and add the ground beef. Break it apart with a wooden spoon, cooking until nicely browned and no longer pink, about 8 minutes. Drain any excess fat.
6. Stir in the diced tomatoes, Worcestershire sauce, and thyme. Season with salt and pepper to your liking. Let the mixture simmer for 5 minutes to marry the flavors.
7. Lower the heat and stir in the sour cream and milk until the sauce is creamy and well combined. Remove from heat.
8. In a large mixing bowl, gently fold the cooked noodles into the beef mixture until everything is evenly coated.
9. Transfer the mixture to a buttered 9×13-inch casserole dish. Sprinkle the shredded cheddar evenly over the top.
10. Bake in the preheated oven for 20-25 minutes, or until the cheese is melted, bubbly, and golden around the edges.
11. Remove from the oven and let it rest for 5 minutes before serving. Sprinkle with fresh parsley for a bright finish.

One thing Mama Lu taught me was to watch your casserole carefully the first time you make it — ovens vary, and that golden crust you’re aiming for is your cue that it’s ready. And don’t rush the resting time; it lets everything settle and flavors deepen, just like letting stories simmer on a porch swing.