Preheat your oven to 375 degrees.
Prepare a casserole dish with cooking spray. We use a dish that is an 8x8 inch square.
If you are using vegetables heat some oil in your skillet, on medium to medium high, until it shimmers or a drop of water flicked in it dances.
Add your prepared vegetables, mushrooms first as they take the longest. Stir regularly until tender.
Remove from heat and allow to drain on a paper towel or in a strainer. Set aside for a moment.
Slice each biscuit into 6 pieces. Cut in half and then each half into three parts. Set aside.
In a large bowl, whisk together the eggs, milk, salt, and pepper.
Stir about ⅔ of a cup of cheese into your egg mixture.
Add biscuit pieces and cooked vegetables to your egg mixture.
Stir until everything is coated.
Dump mixture into your prepared dish.
Bake for 45 minutes or until a toothpick inserted into the center comes out clean.
Add remaining Cheddar cheese to the top and broil for a minute or two to melt and brown cheese.
Serve with some sliced green onions if desired. Serve and enjoy!