Try baby spinach leaves on pizza. It’s not the same texture as either raw boiled spinach.
I also made some saag chicken a few weeks ago that was delicious - it’s an Indian dish made with pureed spinach and tomatoes, and Indian spices.
I didn’t used to like spinach either. I got over it.
How about spinach pesto sauce for your pasta? I made it last night on my caregiving night for my mother.
The neat thing about it is…you get all your food groups in one dish. The spinach and parsley gives you your greens, the parmesan your dairy, whole-wheat pasta your grain, and protein from the walnuts (and whatever meatballs/sausage you serve with it–I broil some chicken or turkey sausage).
There are lots of other alternatives to spinach that you might find texturally pleasing, and that your SO will find palatable as well. Collard, turnip, mustard, and kale greens are all worth a try, also swiss chard which I love cooked with EVOO, S&P, and a dash of hot sauce and/or bacon.
FWIW, my SO likes spinach raw and can’t stand it cooked, and abhors kale in any form. She doesn’t mind turnip greens, though.
+1 on spanakopita! Yum!