There are several brands of frozen meatballs to choose from. Just make sure that the label indicates that the meatballs are fully cooked.
One 4.5-ounce jar of sliced mushrooms, drained, can be used in place of the fresh mushrooms.
These baked meatballs with gravy are delicious with mashed potatoes. To complete the meal, slice fresh apples and pears into wedges, or serve cups of fruit cocktail.