Mix ground beef, egg, sour cream, lentils, salt and pepper, spices in mixing bowl.
Place meat mixture into 9x5 loaf pan. Sprinkle ketchup in a cool design along the top! Sneak in some veggies on this one...finely diced green peppers or shredded carrots would be easy to add in!
Bake at 350 degrees for 50-60 minutes or until cooked through.
Slice acorn squash in half. Bake upside down in baking dish with 1/4 inch water at 350 for an hour. Cover with foil for super tender squash. (See more details here!)
Serve up the meatloaf with some ketchup and butter/brown sugar for the squash if you like!