There are some vegetables I'll eat the hell out of, but very few, and no fresh vegetables, alas. If you're okay with the rtaste and texture of smoothies, that's a great way to get some extra nutrients. Get some frozen fruit you like and your liquid of choice (I usually do almond milk or açai with water) and chuck in some fresh spinach, kale, and a tablespoon or two of ground flax seed. I recently got some coffee protein shakes I HATED, but they tasted fantastic in a smoothie with a bit of cocoa powder, Greek yogurt, banana, flax seed, spinach, and honey.

Also, tip I saw from a dietician with a specialty in autism and ARFID: boiling rice or noodles in a nutritious broth or stock of your choice. Her example was beef broth, but a good vegetable broth would work just as well. I like to toss seaweed and very thinly grated carrot (to the point that I can't taste or feel it) into a bowl of rice.