Preheat oven to 425°
Place onions, mushrooms and garlic in an oven safe dish. Drizzle with 1 tablespoon of olive oil. Toss with fresh thyme, salt and pepper. Roast in the oven for 30-35 minutes, stirring occasionally and until the onions are soft and slightly browned. Dredge Milton’s sirloin beef cubes in the seasoned flour and shake off any excess. Heat remaining olive oil, butter and worcestershire in a large sauté pan over medium-high heat until melted and cook the beef until browned, about 8-10 minutes.
Slowly pour half the broth into the sauté pan and stir with a spatula or wooden spoon, scraping up the brown bits and deglaze the pan. Remove the roasted vegetables from the oven and add to the beef mixture, pouring in the remaining broth. Simmer over medium until broth thickens and is reduced by half. Reduce pan to low and stir in the sour cream, mixing until creamy. Taste, adding salt and pepper as needed. Serve immediately over cooked noodles and garnish with parsley.