If gluten free pasta is not cooked yet, start cooking that first while starting the rest of recipe. When pasta is cooked, drain and rinse in cold water to stop pasta cooking. Set aside until needed in recipes.
Precook ground beef and drain grease, if using. If using stew meat, heat oil over medium-high heat, add beef and cook until browned.
Add onion and saute 3-4 minutes. Add mushrooms, saute 3 minutes. Add garlic and saute 1-2 minutes more.
Push meat and vegetables to edges of pan. Add oil to pan. Add seasonings and sweet rice flour and stir to incorporate flour into oil, browning it slightly – mixture should become very thick. Slowly add broth while stirring with a whisk to evenly incorporate, then slowly stir in milk substitute while continuing to stir until mixture is smooth and cooked to desired thickness. (You can add more milk or broth if you would like a thinner sauce, or increase sweet rice flour for more thickness).
If serving right away, stir in soy sauce, cooked pasta and peas. Continue to heat stirring occasionally until everything is heated through.
To freeze: Follow recipe through cooking sauce until thickened. Then remove pan from heat. Stir in soy sauce, cooked pasta and peas. Pour into 2 deep dish 8"×8" pans or one 9"x13" pan. Cover and wrap well. Label and freeze.
To serve: Thaw. Cook in 350 degree oven until heated through (approximately 30 minutes), removing foil for last 10 minutes of cooking.