In a bowl, combine flour, milk powder, and dry mustard.

Whisk in water and Worcestershire sauce.

Set aside the broth mixture.

Cook onion and ground beef in a large saucepan coated with cooking spray over medium-high heat.

Crumble the beef while cooking, until browned.

Drain off any excess fat in a colander.

Return the beef mixture to the saucepan.

Add parsley, garlic powder, pepper, thyme, sweet peas, potatoes, carrots, and mushrooms to the beef.

Stir to combine thoroughly.

Pour in the broth mixture.

Cook over medium heat for 15 minutes, stirring constantly, until the mixture thickens.

Spoon the beef mixture into a 13 x 9-inch baking dish coated with cooking spray.

Carefully split each biscuit in half horizontally.

Place the biscuit halves over the beef mixture.

Bake at 400 degrees Fahrenheit for 10 minutes, or until the biscuits are lightly browned.