Hi @lindacampagna,
The gastroparesis mantra is low fiber low fat and I was told that I could eat canned asparagus - have you tried that? Very mushy! I couldn't imagine a diet focused on canned asparagus. Being a vegetarian, this was hard for me to digest so I experiment with small amounts of well cooked vegetables and note which I can handle. I can handle canned mushy foods like heart of palm and artichoke hearts. I definitely can't handle raw vegetables because either they get stuck in my throat (e.g., raw carrots) or cause major distress (e.g., fennel carrot diced salad). I can do well-cooked broccoli and cauliflower (see other posts on this stream for more info). I am not a health care practitioner so am not advising your husband to try any particular food but I am just sharing my personal experience.

I find that softer foods work well like tofu over tempeh. I was not able to add powdered fiber because it caused major distress. I can do small serving of well cooked oatmeal but can't do anything with gluten/wheat/seitan without major bloating. I can do 1/2 small apple. I chew my food for what seems like a ridiculously long time and drink room temperature water with my meals and throughout the day. I also do 5 to 6 very small (kid-size) meals so it seems like I am always grazing! 🙂 I try to eat nutrient dense foods like guacamole and thai peanut dip. I think the reason that I can't do store-bought tzatziki is because of the raw cucumbers but I haven't tried making my own without cukes or with the skin and seeds removed.
I found it difficult for a spouse to adapt because they have trouble understanding why I just can't eat three normal-sized meals a day but over time seeing my distress finally lead to understanding. Keeping notes helps.
Wishing you the best!