Sunday batch cook
One pot of chilli or curry, six portions in the fridge/freezer, lasts the working week. Add rice or jacket potato in 10 minutes when you get home. Maybe £15 of ingredients for the week.
Packed lunches matter more than dinners
A site meal-deal is £6 minimum. Five days × £6 = £30/week × 6 weeks = £180. A sandwich + crisps + apple from your own kitchen is more like £1.50 × 30 days = £45. £135 saved per stint.
Shared kitchens, shared meals
Crews who batch-cook together and rotate cooking nights eat better, save money, and bond. Each person cooks one night, the others wash up. By Friday everyone's been fed properly and nobody had to think about food on a Tuesday after a 12-hour day.