I buy the pork ribs from tesco when they are reduced (it's a pack of individual ribs) and cook them low and slow as per Nigel Slater with carrots, onions, stock and other veg for 3 hours. I then pull the meat off the bones, and I have a pasta ragu. I used 4 packs of ribs last time (total cost of the ribs just over £3, as they had been reduced and reduced again), and I got enough ragu for 16-18 portions; not bad.
I did Bloody Mary beef by Jamie Oliver for Father's Day (meat cost £11 for a 1.7kg brisket), and I had everything else in. That fed 7 on the Sunday and Monday (so 4+3, as I gave a portion to Mum, and ds and I had it on the Monday as I cooked something else for dh), and I have still frozen another two tubs, one for 4 and one for 3. Again, not bad going.
Stewing beef is great if you have some good recipes, and again, I cook a huge load and then freeze for later. I also see what offers the local butchers have. We have two very good ones butchers, so I buy according to what is on offer. I still have pheasants in the freezer from when they were cheap.
I also get bags of bacon offcuts from the butcher, so that's carbonara, used in a bolognese, an amatriciana, a risi e bisi, omlettes and a fridge pasta.
Bacon bits, loads of veg (onion, leek, carrot, sweetcorn), stock and milk can be used to pad out the remains of a chicken, then topped with sliced potatoes or filo for a pie. You can add spinach or chard to the sauce as well.