Ok, so I know some of these don't involve cooking but...
Zucchini and vege slice, frittatas, quiche, omelettes, french toast or just a straight boiled egg cut into quarters. You've already mentioned muffins, but they're so versatile and freeze well! Vege pancakes? Vege pasta bake with spirals or penne? Rissoles/meatballs/burgers/patties etc (DS liked lentil burgers for awhile there). Lasagne? Cheese sauce for dipping the veges into. Cheese on toast (I sneak in things like chopped spinach) with mashed avo. Sultanas? Dates? Olives? Tomato? Cucumber?

Have you tried mucking around with how much you cook/present the veges? I know DS likes some less cooked, and some more (if they're too hard he won't eat them, so stir fries are still out, but if the zucchini for e.g. is too soft, he prefers playing with it to eating it!). Keep presenting the veges too - it took DS about 20 goes to like some veges, and some he'll eat on some days but not others, depending on his mood. The shape makes a difference to him too - he won't eat banana sliced, but will sometimes peel and munch on his own. Some days the strawberries are sliced, some days they have to be whole. If he sees us eat it, he'll try it, so eating together is a must. A friend's DD won't eat 'squishy' finger food either, but put it on a fork and she devours it! I know another girl who eat all sorts of food without teeth (e.g. chops!) so you might be surprised at what he'll get through.