I had been mulling over your meal issue and it is a tricky one. That being said you do need to stand up to it. This is a boundary about you and about being an example to your sons. I agree with LouR that if you are walked over in front of your sons,they could follow that example.
But even from a simple manners point of view it is a bad example (speaking about H not you!!!) I personally would say to him that his behavior is not an acceptable example for your sons. Maybe he would push back less from that standpoint as opposed to you not liking how he is treating you.
I think that in his current state of mind he would prefer to make this about you and him . He gave you the extreme silent treatment for a week because he did not like what you said to him. He was vexed about not getting his way about the two cars. Right now no matter what you do or say he takes it personally and is angrier with you. To him YOU are the problem.
Don't let fear of his reaction stop you standing up to him, but be mindful that some approaches and wording could be easier turned against you. No point it stirring a hornets nest if you can just fumigate it.
I don't like the idea of dumping his dinners. It is provoking him and wasting good food. I do like your suggested approach. I am impressed that you found such a humane response. Approaching H beforehand is perfect. Much better than just not preparing his meal, which no one would blame you for by the way. I think that throughout this situation we should strive to behave the best we can regardless of what they deserve.
Can I ask you why you are not a WAW? I may have missed this point in SN earlier thread. If so sorry. I don't want you to walk sway, but I am curious as to your mindset. Recently you doubted if you would want him back, yet you stick out your situation. Many would have booted H out long ago. Yet you have patiently endured his antics. I admire your stance and your patience.II am just curious about your inner thinking about where YOU are at.
Best wishes
R 25 years M 14 years S11 & S13 Working on it alone since Oct 2014 M in trouble a lot earlier (~2 years) Feb 2016. 1st R chat in a yr. Next R chat Aug'17 Still together