I don't ever buy those 3 for £10 offers, they are usually a false economy.
Approx £10 gets me (in Asda):
1 packet of turkey mince £1.60 - serves 4 as a bolognese or 2 as 1/2 bog and 1/2 burgers
1 packet of skinless halal chicken thighs - you get approx 8 in the packet - £2.59
1 small smartprice roasting chicken £2.50 or less -cheapest I ever found was £2.17
1 pork tenderloin for approx £3 or whatever meat we fancy for roast if we had our chicken through the week.
Then I go to Tesco and buy meat free burgers (2 packs of 8 for £3) (1/2 a syn each)
A large jar of organic passata for bolognese (89p) and a pack of organic pasta twists (59p)
15 value eggs
1 pack of Healthy Living brown oatbran rolls
1 small brown loaf
1 pack of low fat sausages, whatever's on offer that week
Veg wise, if I go to a supermarket and not the veggiestore I normally get a pack of red onions, a pack of baking pots or whatever pots are on offer, and the rest of my veg I buy loose, so like 4 large carrots, a half swede, mushrooms, a butternut squash and a head of broccoli. I also get apples and bananas. If i'm feeling flush I'll get grapes too or a punnet of plums.
And I get a batch of whatever yogurts are the best offer. This week I got my 12 Mullers from Morrisons, last few weeks I've gotten the two 6 packs of mullers for £3 from Tesco. You will usually find that on any given week, you will be able to get Fuller for Longers, Activia Fat Free or Weight Watchers 4 packs for £1 in either Tesco, Asda or Iceland.
Iceland ALWAYS has Pasta n Sauce for 89p each on BOGOFF, ALWAYS. But if for whatever reason I can't get them, I go to Home and Bargain, where they are 49p each.
This week, our Asda had 8 packs of the Crosse & Blackwell chicken and mushroom pasta n sauce for £2. So I got three packs cos they last forever.
My storecupboard essentials are mainly oregano, Fry Light and all flavours of OXO. And packets of boil in the bag rice - these are great for making sure you don't go overboard on the 'free food' portion. Asda and Tesco both do an own brand version which is much cheaper than your average Uncle Ben's etc. Tins of value toms, value beans, value tuna and tins of mushy peas - don't skimp on these, buy Bachelors! I also always have to have Weetabix in the house for those times I'm rushing and don't have time to weigh, measure or cook a breakfast. The store's own brand will be perfectly tasty and cheaper too. You'll also want a jar of extra light mayo and a pot of natural fat free yogurt or fromage frais.
If I can afford something treaty I will go to Marksies and get a couple of cans of their stewed steak, syn some red wine and add button mushrooms and red onion and serve with butternut mash and broccoli. Or I'll get one of those frozen salmon roasts from Tesco in the lemon and tarragon (I think) glaze which is a fiver and free on red. Or something new and treaty from the latest SW magazine.
That should come to around £40 per week and I save a tenner for things like when the milk runs out or if we fancy something else or I come across a recipe and need some vital ingredient.
Hope that helps.