My DC at 1 was very very fussy.
I second not buying crisps etc and hiding vegtables in pasta sauces etc. My DC consider a yoghurt as a dessert and they like your DT are not keen on fruit (but will happily munch on raw carrots, peppers, cucumbers as a snack).
A few suggestions:
Quesadillas:
fajita flat bread, with a combo of cheese, homemade tomato sauce (you can hide your vegetables in this) and ham/chicken (if they will eat it, but you could sneak it in). You then fry (in light oil) on both sides, then cut and serve (very similar to a cheese toastie but a Mexican version).
Home made pitta pizzas:
Pitta bread, homemade tomato sauce (with hidden vegetables), cheese and any other 'pizza' toppings. You then grill and serve with a salad (cucumber/carrot sticks).
Loaded Yorkshire puddings:
Make Yorkshire puddings (homemade are so much nicer) and fill with, sausages/chicken/ slow braised beef in a sauce (hidden vegtables in a gravy type thing).
In all the above you could get your DT to help, which may get them to at least try it.
Also, if you are giving them biscuits/crisps; maybe make your own (you can use less sugar or use an alternative), and even limit these to just once a day.
And to end, it is well documented that young children must taste something at least 15x to get used to it. So even if they say 'no' (I mean in regards to dinners) serve it anyway (children will never starve).