Laura33, you always give such wise and down-to-earth advice that I'm not sure any of us can give you any ideas you haven't already considered or tried :) But since I have thoughts on the subject and they don't seem totally dickish, I'll share them (and maybe the outside perspective is helpful, I dunno).
Obviously frugality is an issue at stake here, but more fundamentally you have a difference in values with respect to food. You prioritize eating what's available; he prioritizes eating what he wants. You have different ideas of "healthy". You take food waste as a more serious threat to both your finances and your world. And as two adults...you can do whatever, who cares. But you have kids and every day you're modeling for them what's a sensible approach to food, what's deprivation, what's a splurge. His example is setting your kids up to go off to college and ignore their mandated meal plan in lieu of getting pizza or Chinese or burgers every night because they feel like it. I think if you are to move forward you really need to reconcile this: the values standpoint, the question of "what's our default behavior and what are good reasons to deviate from it?"
I've basically brought bf around to the consensus that our default is cooking (it helps his family growing up functioned this way, too); if we're tired or lazy and cooking Will Not Happen, cooking convenience food (frozen pizza, frozen dumplings, pasta) is ok; and only as a last resort going out for convenience/outsourcing. But on the flip side I put up little resistance to going out for socializing or entertainment occasionally, especially since he works from home (we do still have people over, and do other non-going-out-to-eat things as well), we eat out when we're "on the road" (tbh, I've never been driven to change this), and I try not to overstock the fridge so we aren't stuck eating leftovers that are about to turn or using up old produce *all* the time. I also concede to eating pork sometimes, which he likes more than I (though never 2 weeks in a row...).
If I was in your shoes, I would approach the conversation by first emphatically explaining that this is *important* to me, with or without supporting reasons (they can strengthen your position but also sidetrack you into a debate), and that I need help in accomplishing this; then I'd reassure that I understand that his preferred behavior/approach brings him a lot of enjoyment and by no means do I want to cut him off from that...but could we maybe come up with some guidelines for what we consider a reasonable amount of pleasant behavior to engage in (frequency, budget, exceptions, whatever). And then I'd also ask, what can we do to make the less pleasant behavior more palatable (e.g. focus less on your definition of "healthy" and do more red meat; or plan a sequence of meals with the same protein but different cuisines: we did poached chicken in tacos, on pizza, in fried rice, and would have done bbq sandwiches if the bread hadn't molded :( . Shrimp can be in a lemon-butter pasta, or in Thai fresh rolls, or in stir fry, or in tacos, etc..."modular" meal-planning, of sorts?) It probably won't go smoothly, it might actually be several conversations, the execution will probably go off-track at some point...but that's how I'd look to deal with it.