£7 per person week1

Assumptions

• £7 only for the whole week; precludes buying cheaper (larger) value packs at the beginning of the challenge
• 3 meals a day plus drinks for 1 person
• No offers sought
• No vouchers/coupons redeemed or reduced (e.g. for quick sale) items included
• No free food or swaps from family and friends
• no storecupboard; we have actually had this happen when we moved back from Germany, but had budgeted for it so that we could restock the first supermarket shop - v. expensive though!
• Prices are from Tescos for ease of use and may or may not be cheaper elsewhere for particular items; were this for real I would be using a price book and comparison sites such as mysupermarket.co.uk for the best deals
• If you haven't got a storecupboard you probably haven't got a freezer or food processor and other such fancy stuff so minimum of expensive equipment used

If I can keep within the budget with these limitations then anyone doing it for real would be able to snap up deals and do it for even cheaper or add more variety.

Drinks
Unfortunately I cannot function without a cup of tea in the morning and at the start of week 1 that means teabags, milk and sugar and a big hit on the purse just for the wet hot stuff. I am assuming I could limit myself to 3 cups a day and this would use 1 pint of milk and 1/2 a small bag of sugar (just a guess as I don't use it myself but we are going for worst-case finances here), the rest of the time I would make do with tap water. 
Tesco everyday value teabags (80 bags) - 27p - assuming 3 cups a day about 26 days worth
1 pint whole milk -49p by buying whole milk I could water this down half and half and end up with 2 pints semi-skimmed for the price of 1
granulated sugar -(500 g) 79p
£1.55 spent £5.45 remaining

Breakfast
Using my other pint of milk cunning scavenged from above along with the sugar I could have breakfast cereal.
Tescos everyday value cornflakes (500g ) 31p - Tescos own figures give a serving size of 30 g so this is 16 days worth of cereal.
£1.86 spent £5.14 remaining

Lunches
Bread Tescos own label medium sliced loaf 69p about 22 slices
Margarine - everyday value sunflower spread 500g 75p
everyday value baked beans in tomato sauce 420 g i.e 2 servings 26p
everyday value cooked ham - 10 slices 61p

£4.17 spent £2.83 remaining

Dinner
Spaghetti - everyday value spaghetti 500g 24p assuming a 75 g serving this is 6-7 servings
Tesco Sieved Tomatoes Passata 500G 29p (3 servings)
head of garlic 30p (assume 6 cloves garlic)
jacket potatoes (4 in packet) 75p - serve as jacket potatoes or as mash
everyday value coleslaw
tescos everyday value pork sausages 8 in packet 56p
4 (loose) carrots 34p
spent £6.91 9p remaining

carried over to next week:
3 portions of pasta 
4 sausages
19 days worth of teabags
9 days worth of cornflakes
half a head of garlic
half a tub of sunflower spread
half a bag of sugar
plus 9p 

shopping list
Tesco everyday value teabags (80 bags)
1 pint whole milk granulated sugar -(500 g)
Tescos everyday value cornflakes (500g )
Tescos own label medium sliced loaf
everyday value sunflower spread 500g
everyday value baked beans in tomato sauce 
everyday value coleslaw
everyday value cooked ham
everyday value spaghetti 500g
Tesco Sieved Tomatoes Passata
head of garlic
jacket potatoes (4 in packet) 
tescos everyday value pork sausages
4 loose carrots



Day 1
3 cups of tea throughout the day – otherwise tap water
breakfast -Cornflakes with milk and sugar
lunch -2 rounds ham sandwiches
dinner -Jacket potato with coleslaw
Day 2
3 cups of tea throughout the day – otherwise tap water
breakfast- Cornflakes with milk and sugar
lunch- 2 rounds ham sandwiches
dinner -Pasta with garlic and tomato
Day 3
3 cups of tea throughout the day – otherwise tap water
breakfast-Cornflakes with milk and sugar
lunch- Beans on toast
dinner -Sausage carrots and mash
Day 4
3 cups of tea throughout the day – otherwise tap water
breakfast-Cornflakes with milk and sugar
lunch -2 rounds ham sandwiches
dinner -Jacket potato with coleslaw
Day 5
3 cups of tea throughout the day – otherwise tap water
breakfast-Cornflakes with milk and sugar
lunch-2 rounds ham sandwiches
dinner-Pasta with garlic and tomato
Day 6
3 cups of tea throughout the day – otherwise tap water
breakfast- Cornflakes with milk and sugar
lunch -Beans on toast
dinner -Sausage carrots and mash
Day 7
3 cups of tea throughout the day – otherwise tap water
breakfast-Cornflakes with milk and sugar
lunch-2 rounds ham sandwiches
dinner-Pasta with garlic and tomato

As a first attempt it has the right number of meals (so it can be done) but is a tad repetitive and you would have to like baked beans and tomatoes an awful lot!