Preheat oven to 350 degrees then coat 9" x 13" casserole dish with non-stick spray. Prepare long grain and wild rice according to box directions then fluff it with a fork and set aside.
Place large skillet over medium-high heat then add ground beef. Cook 5–7 minutes or until no pink remains, breaking meat into small pieces as it cooks.
Add mushrooms, onion and garlic then cook 4–5 minutes until the onion becomes translucent and mushrooms soften.
Drain excess grease from skillet, return to stove then reduce heat to medium. Sprinkle flour over meat mixture then mix until flour has dissolved completely. Cook 2 minutes, stirring frequently then add beef broth. Stir to combine, scraping up any brown bits stuck to the bottom of the pan.
Bring liquid to boil then add thyme, paprika and oregano. Reduce heat to medium-low then simmer for about 5 minutes. Stir in milk, return to boil then reduce heat once again and simmer 5–6 minutes or until the sauce thickens slightly.
Add Parmesan cheese and prepared rice blend to the beef. Stir to combine then adjust seasoning with salt and pepper if necessary. Transfer mixture to prepared casserole dish then top with Italian cheese blend.
Bake uncovered 20–25 minutes or until the center is hot and the sides are nice and bubbly. Let casserole cool for 10 minutes before serving.
Coat a wooden spoon with sauce then run your finger through the sauce to test thickness. If the line created stays intact, you’re there!