Heat the oven to 400°F. Toss sweet potatoes with oil, then roast for 20 minutes.

Cook sausage in a skillet over medium heat until no longer pink. Drain extra grease.

Whisk eggs, milk, salt, and pepper in a bowl.

Grease 12 muffin cups. Divide sweet potatoes and sausage among them, then add egg mixture and cheese.

Bake for 18 to 20 minutes, until the centers are set. Cool completely before freezing.

Freeze in a sealed container. Reheat one cup for 45 to 60 seconds, checking the center before serving.