If you are working at home and have three to feed, then I would suggest a roast chicken. It is good value and a lot less work than you might think and is usually enough for two meals - once hot, then leftover chicken pieces fried up later with cooked rice, peppers, celery and chopped tomatoes for a second meal.
OK, to roast a chicken. Roughly two hours before the meal is due, heat up oven to No 5 / 375F / 190C. Put chicken on roasting tin, ideally one with a trivet or tray that holds the chicken above the tin (so it gets less fatty). Put salt, pepper and mixed herbs, if you like them, on chicken skin. Put chicken in oven and cook for 20 minutes per 500g plus 20 minutes over (so 100 minutes for a 2kg chicken, which is a good size to last two meals).
About an hour before the meal, peel potatoes (ideally King Edward or Maris Piper, say two or three per person, more if the potatoes are smaller or the people are hungrier) and cut into pieces. Boil for about 15 minutes until just cooked. Meanwhile, put another roasting tin/tray into the oven with whatever fat or oil you have - maybe olive oil? Let heat through for 5 minutes, then put cooked potato pieces onto tin/tray, turn potatoes in fat/oil so that they are coated and put in oven on the top shelf. Turn potatoes over after, say 20 minutes or when you remember. Just keep an eye on the potatoes to stop them burning, or turn up the oven to No 7 or equivalent for the last 10 minutes if they look very pale. Prepare and cook any other vegetables as you like.
Written down, this looks more work than it is, and the timing doesn't need to be very accurate, except for boiling the potatoes. The roast potatoes are more work than the roast chicken, but so popular with my DSs it is worth the effort. I hate to confess this, but I tend to make lots of extra potatoes and they are always gone by the end of the evening - down the DSs' throats, not mine! They snack on them through the evening, when they get those teenage hunger pangs an hour after the last meal.
You can ring the changes by stuffing the chicken with packet stuffing (and increasing the cooking time by about 10 minutes for the extra weight) or by putting bacon rashers over the breast at the chicken, but both are completely optional.