How to divy up the chores

I realize I got myself in this current position by assuming responsibility for everything my spouse left undone.

So, now in this grown-up world of no parenting my husband, what do I do?  Literally, what are the steps.  I cook on my agreed upon day.  My spouse forgets his day.  I cook on my agreed upon  day.  My spouse forgets his day.  Right now, I cook if I want.  Otherwise, it is every man for himself.  You find it, you can eat it.  

That just seems so wrong.  And feels very lopsided  for me.  He doesn't care.  I do.  Now what steps do I take for this situation.   And what about the grocery shopping?  

I guess some may think this is humorous.  It really sorta is, no doubt about it.  Grown people bickering over chores. The good news we no longer talk about it.  No arguing.  No snide comments. But, this just ain't right.    I just need some lead on how to adjust it all.