If your husband has actually been talking about wanting to do processed-free, then it sounds as though he is at least open to trying a few things. I just want to point out that corn is not a vegetable, it is a grain, so really your husband only likes two vegetables! Oh my!
If a person does not like fruits and veggies, I always recommend "drinking" them instead of eating them, at least just to get you started. My best recommendation is a whole food product called "Amazing Grass." It comes in a berry flavor and a chocolate flavor, and is best mixed in a blender with a bananas and some juice or some type of milk (almond milk, rice milk, or coconut milk).
Amazing Grass is made of dehydrated vegetables and fruits, and green "superfoods" like wheat grass. It is highly concentrated nutrients and the best way to get some good fruits and veggies into you.
Fruits can also be blended into a smoothie, and sometimes the best ones are just bananas and strawberries with a little bit of water or ice to thin it out.
Meat and potatoes are not bad, but they need to be balanced by vegetables. Start slowly and try something new and then stick with that. Adults can be set in their ways about food. I was like that myself. I only like a few veggies myself when I first started eating healthier. But I found that I had to keep trying, and discovered that eventually I did like more vegetables and fruits. I had to stop being so stubborn and became willing to try new things. Some things I liked, some I didn't. But I did eventually expand my repertoire.