Hi Kori - I feel your pain! My little guy was doing the same thing at 15 months- it was a really fun "game" - for him that is!
Dont forget that he should be getting 24-32oz of 2% or whole milk per day at his age. The fat is really important for his brain development and calcium for bones/teeth. I like the Horizon milk that has added DHA. Cottage cheese and whole milk yogurt count toward the requirement.
We broke my son's habit (for the most part) by giving him only his fork or spoon but then putting his plate or bowl just out of his reach on the table. That way, he couldnt start messing with his food until I was able to sit down and he had a chance to get interested in it. If your guy is in a highchair, you might consider keeping control of the food and feeding it to him one piece at a time until he learns.
I would usually offer him a spoonful or a tidbit and when he knew it tasted good, I would give him his plate. We also only gave him small amounts of food at a time - it was easier for him to focus on small portions, it was easier for me to clean up, and it wasted less food. The other thing we did was make sure his snack time and meal times were at about the same time every day so he would be hungry.
When we stopped using the high chair, we set up a booster and chair for him that is the only place he eats or drinks. He has a picnic table that he has to sit at if he eats outside. If he throws his food, then that meal is over and he has to get down from the table. It didnt take him long at all to start eating and stop throwing. There were plenty of testing times. I would just clean him up and take him out of his chair, even if it was only for a few minutes. It was the fact that he had to stop eating and get down that reinforced the good habit.
To help with the veggies, etc., I either soft cooked his veggies and mix them in with sauce or melted cheese etc. or I blend them completely into the sauce. Adding butternut squash puree to mac & cheese is really easy and I mix in some well cooked peas and carrots and sometimes tuna. I like to use the penne noodles because they hold sauce and they're easy to eat with their hands. Remember, just a 3-4 noodles at a time.
Tomato sauce is also really easy to make - I add grated carrots and added some fresh spinach to my recipe. My son really liked small raviolis or tortellinis either in spag. sauce or even with just tossed with a little olive oil and parmesan. It also tastes good with very small well-cooked pieces of broccoli. He also liked little meatballs. Sometimes I add cooked rice and cheese to his before I baked them.
Hope that helps to give you some ideas - mostly just try to set it up so that mealtimes are about eating and not about play.
Good luck to you!!