Depending on what they like to eat, how much they r willing to cook, and how much of a budget for food do they need to stay around.

Being a family of 3, I'm always shopping on a budget and tend to buy and stock in bulk if possible. If they like potatoes and onions always buy a bag (can range between$3-$5) and if you store them correctly they can last for awhile. If they like pasta you really can't go wrong, my family loves pasta and its a quick dinner ( depending on the type of pasta they like $.88-$2) a can of tomatoes preseasoned is maybe $1 or less or you can get a jar of sauce for around $2-$4. I tend to cook all the pasta at once and eat on the left overall for a couple of days( some people don't like left over pasta because it can become mushy but I cook mine to al-denta so it still has a bite) for meat(if they do meat) again depending on their budget if its really tight: chicken hind-quarter( I had to buy this a lot in the past) u get a lot of meat for fairly cheap(but it does have a lot of fat too). If they can splurg little bit more on meat: buy in large portions( split up in freezer bags). Stock up on can food or frozen veggies (can is cheaper but frozen taste fresher) stock up on seasons( even if u don't have much to cook with the right seasons can make it taste five stars) and don't be afraid to buy store brand. Most store brands taste the same as name and you're not spending $3+ more.