Some tips. Mashed potatoes you can add root vegetables like carrots or celeriac root to extend the volume of dish.
Potato casseroles with added vegetables.
Rice with things mixed into it like peas, beans, corn, colorful bits of bell peppers.
Beef stew from less expensive stewing beef cuts cooked for few hours until fork tender a little sugar and spoon of apple cider vinegar will help soften the beef.
Save bits of vegetables and store in a bag in freezer and end of week you have start for a soup.
Ovenroasted chicken just seasalt pepper and some citrus lemon and/or orange and it roasts in its own juices.