sorry about that!
I was going to say, use the things he eats - rice pasta bread etc and add to it. you can buy or make pasta that use vegies instead of wheat eg pumpkin gnocchi. You could also get a juicer and get him juicing vegies and drinking them out of a cool glass with a special straw. i think getting them involved with the cooking is really important. My dd is 3 and has been involved with the cooking since she could sit on the bench. She chops the vegies for us, can make scrambled eggs, she is allowed to do anything in the kitchen except use the stove or appliances. Sometimes we give her a heap of ingredients and let her do whatever. it doesn't matter if she makes a mess. its part of learning. tonight she made herself a pizza. but I definatly do think that by continuing to give the not so good foods - you won't break the cycle. Not sure what your own eating habits are, but you may need to stop buying the stuff you don't want him to eat otherwise its a little hypocritical if sees others eating it.
Some food ideas :
toasties
avocado on toast
eggs on toast
scrambled eggs with very finely chopped spinach, cheese and natural yogurt
wholemeal pancakes with grated apple or mashed banana in them using natural yog and milk.
pancakes with cheese in them
savoury pancakes - basic pancake mix toped with tomato based pasta sauce and cheese and then grilled.
enchiladas/burridos
quesidillas - 2 tortillas with cheese, shredded chicken, pineapple, avocado
dry fried in a pan or put into a toasted sandwhich maker (the flat ones)
chille con carne
baked potatos
soups with big dollops of sour cream or natural yogurt
steamed vegie dumplings
even interesting foods that you can dip or eat off a stick satays etc...
also don't think they only eat bland foods. my dd loves all sorts including curries, hot pots and things that are spicy or sour. even my 8 month old enjoyed some potato from a masala curry the other night!
a lot of food issues stem from exposure to foods, being under pressure when eating - which starts from the first moment you give them solids and also the families attitude to foods. If you try and give a generally healthy diet, but use a lot of processed fatty, salty or sugary foods as a treat or quite regularly - you will train their tastebuds to seek these foods out. The consequence is also that other foods taste bland.
I did this myself and was surprised at how awful the things I was used to eating tasted. I used to have packet cake mixes or flavourings for slow cooker, soft drink etc. Not a lot, but maybe every couple of weeks. I decided to give them all up after becoming pregnant and reading about each individual ingredient. After 6 months I had a sip of soft drink and it just tasted like chemicals. Same with a packet cake mix. It tasted like chemicals. As long as I was eating them, my palette was stuffed. Same goes for kids.
I know that was heaps of info! I am very passionate about this topic! I am more then happy to answer any questions if you want me to expand on anything.... but basically, this is all about teaching good food attitudes from the start. That is why I don't believe in bribing or tricking kids into eating. I think they should be encouraged to ENJOY the food, rather then it being something they have to do.
All the best with it!