Heat oven to 350 degrees.

In a large bowl, beat egg and milk.

Add in oats and cheddar cheese.  Mix well and allow to stand 2 minutes.

Add in onion, salt, and beef.  Mix with your hands until incorporated.

In a separate bowl, mix ketchup, brown sugar, and mustard.

Grease a 12 cup muffin tin.  Divide beef mixture up evenly in the 12 cups.

Add about 1 tablespoon of topping onto each meat loaf.

Place the muffin tin on a cookie sheet to catch any spills during cooking.

Bake at 350 for 24-29 minutes or until a meat thermometer reads 160 in the center of the meatloaves.