1st meal, roast chicken. Sometimes whole chicken is the cheapest, but sometimes chicken thighs or chicken leg quarters are the better deal. If I'm not cooking a whole chicken, I cook one piece per person eating (unless they're leg quarters, then I'll cook one quarter per 2 people eating) plus extras for future meals. It uses almost the same amount of electricity to run the oven to cook 10+ pieces as it does 5, so why not?
All chicken scraps (bones, skin, meat bits, pan drippings) are saved. After dinner, all bits of chicken that can be salvaged are picked off of the bone (there's a surprising amount of meat on the back, and that often gets forgotten). Chicken meat put in the fridge, and all the scraps and bones put in a pot, veggie scraps from the freezer (if I don't have any in the freezer, I'll just cut up some onion, carrots, and celery to add to the pot) added along with other reserved bones (if I have any), covered with water and a splash of apple cider vinegar, and simmered to make chicken stock.
It's important that the chicken be served with lots of sides to help stretch the meal. Roast vegetables along with the chicken to make them extra tasty and to conserve oven power.
2nd meal: Something like chicken & dumplings can be bulked out with veggies added to the stew, plus veggies on the side. For people who have no issues with potatoes, it can also be served on top of mashed potatoes to help stretch a little further. Mashed cauliflower or other veggies could also work just as well. Use the chicken stock to help make this too.
You could instead try making chicken pot pie or chicken shepherd's pie. Again, lots of veggies is key.
3rd meal: white chicken chili? Stretching the meat with beans also helps to bulk up the meal, plus the chicken stock contains a lot of the goodness from the chicken.
4th meal: chicken soup -- chicken noodle, chicken rice, chicken barley, chicken vegetable, whatever your family likes.
There's almost always soup or a serving of one of the other dishes for another meal for someone.