One of my favorite quick dinner recipes is Shepherd's Pie.
I usually double this recipe (in a very deep 9x13 pan) and I usually get 3 days (not in a row) of leftovers for me and the boys. (Hubby is gone in the evening for work alot.)

1 lb ground beef or turkey
1 small onion, chopped
pkg of dry brown gravy mix
salt and/or pepper to taste
a few shakes of Worchestershire sauce
16 oz frozen mixed vegetables
instant mashed potatoes (4 servings, prepared according to package directions)
1 cup shredded cheese (more if you like cheese)

PREHEAT oven to 350 degrees.
BROWN the ground meat. Pour off fat.
SAUTE the onion with the meat.
ADD salt and pepper to taste.
MIX the gravy mix with 1/2 cup of hot water and whisk until smooth.
PLACE the ground meat and onion in the bottom of a 9x13 baking dish.
POUR the gravy over the top and ADD the Worchestershire sauce.
POUR the vegetables evenly over the meat (I put them on straight out of the freezer).
SPREAD the potatoes evenly over the veggies.
TOP with the shredded cheese.
BAKE for 35-40 minutes.