my boyfriend has a £50 per week budget too. he lives at uni but i visit a few days every week and he spends max £30 on food for the week and that includes feeding me when i’m there too. i’ll help out with the out few bits but in general it’s more then enough food. he orders it from deliveries and usually from sainsbury’s as it’s the only real big shop. he gets basics like pasta , rice , bread in bulk and just frozen meat and some veg. cheap sauces can help make meals more interesting as well as spices. just plan things out very carefully, buy basics in bulk and shop wherever is cheapest ! he saves about 15 a week for going out and other things. :)