My kid used to love broccoli, but then gave it up, too. Drives me crazy. I keep telling him he can't be vegetarian and not eat vegetables!
There are some juices like Odwalla "Superfood" and Bolthouse Farms "Green Goodness" - that have some healthy greens in them. Not as much as a bowl of brocolli, but some. It has a dark color, so if you think it will freak your kid out, put it in some cup with a straw so they can't see that it's a green fruit smoothie.
For spinach, I've been able to add a little chopped spinach to spaghetti sauces. Trader Joe's makes a "Cattiatore Simmer Sauce" and I add some *finely* chopped spinach and faux chicken (vegetarian "chicken") to that and toss it with angelhair pasta. (The simmer sauces are made to go with chicken or other meat, but the Cattiatore would be good enough on it's own.)
It's always easy to add more veggies to a soup recipe. Experiment with soups - my 4 year old has been BEGGING me to make the "Smashed Pea and Barley Soup" recipe that I got from the California Pizza Kitchen Recipe book. (Let me know if you're interested in that recipe.)