We make a lot of pizzas on the grill. I usually take a small yellow onion and grate half of it and them sweat it with a minced garlic clove in a little olive oil in a sauce pan. Then I add a can of either tomato sauce or crushed tomatoes and then simmer it with a little sugar, salt, pepper, oregano, basil, crushed red pepper, etc. Basically, I just add a little of this, a little of that...tasting as I go and adjusting as needed. I don't measure and it turns out a little different every time....but always better than any store bought sauce.
Are you using a Weber kettle? Do you have a WSM? If so, here's how I do things...if you want to give it a try.
Take the charcoal ring from the WSM and put it on the charcoal grate of the kettle. Then put 1 layer of unlit around the outside of the ring. Dump a full chimney of lit on the unlit. Put a couple of fire bricks on the grill grate and put the stone on top of them (you want to raise the stone up some so it's closer to the top of the kettle and the radiant heat will cook the toppings faster and at the same rate as the crust). Let the stone preheat for at least a half an hour before putting the pizza on. 10-20 minutes later (depending on how hot things get) it's done!
Thought I had some pics of my setup but can't find them. Here's one from someone over at TVWBB.
