If DP needs meat, would a pack of bacon lardons be enough to "flavour" a meal? So maybe a caesar salad with bacon, omlette with mushrooms and bacon and cheese, macaroni cheese with bacon and lots of veg, or pasta with tomato sauce and bacon and veg. Or bacon sprinkled over a jacket potato?
Taking that further, (we'd often get the Lidl bacon lardons pack, and one portion can be enough for carnivore DH to feel like it's a "meat" meal). If you get a joint of bacon (often large ones are very good value), boil it and have bacon meal, use the water with a pack of frozen peas to make "ham and pea soup" for another meal, and portion up the rest of the bacon for sambos, and in chunks for meals as above. Leftovers can be frozen and are fine defrosted for mixing into things.
Stretching a chicken is another great thing to do. Roast your bird, and enjoy the roast dinner. (I usually try to only roast enough spuds for the meal, or use leftovers as "homefries", either grilled or fried, but do loads of veg especially when using medditeranean types, to use with pasta etc next day). Take ALL the rest of the meat from the carcass (it can be frozen) and use it for various dishes (sambos, omlettes, pasta dishes, curries or asian stir fries, risotto, pies, chick and mushrooms with cream sauce (or campbell's chick or mush soup) etc). But then use the bones to make stock - with a carrot, onion, celery (if have it), some pepper and some herbs - boil it up and then take some for freezing/using as stock, but blitz the veggies into remainder as soup (take out stalky herbs before that point).
For mince dishes, I add loads of veg to it too. So spag bol is made with 500g mince, 2-3 carrots, a courgette, half a pepper, handful of mushrooms, big onion, 3 cloves garlic etc, and the tin of tomatoes. And that then serves about 6 adults. I know my DSis does it using all "orange" veg - carrots, butternut squash, red lentils etc, and is able to stretch it even more. For shepherd's pie, I do the same only tend not to use pepper, but add frozen peas instead and I do use lentils (green/puy? something like that) in that. Leftovers are also frozen.
Frozen veg is good (the kind you buy in freezer aisle), check yellow stickers and freeze veg at home too. I also pick up the stalks of the brocolli plants (in our SM, they have a hacksaw to cut them off, but allow people to take them home "for the rabbit" - I often bring a bag if they are thick). So I'll buy the head as usual, but the bag of stalks comes too. The outside skin and the stringy bit just inside are peeled off, and then I use it sliced up in stirfries, or diced into my mince dishes as part of the veg mix. (I noticed after I started doing this, that I suddenly recognised one of the ingredients in my Chinese takeaway!!). It's tasty and nutricious, just not something most people think of using.
Hope those bits help.