There are two important components to a creme brulee: the custard and the caramelized sugar crust. You could argue that the crust is even more important than the custard, as that is what sets it apart from other custard desserts. There are a couple of ways to make the crust. The most common in home kitchens is to use a small kitchen torch, which will enable you to caramelize the sugar without heating the custard too much. Sticking the ramekins under the broiler will do the same thing, but does put you at risk of putting too much heat onto the already cooled custards if you don’t watch them closely.
One other tool you can use is Steven Raichlen’s Crème Brûlée Salamander. This is a cast iron plate (with a handle) that you heat on the grill, grab with a pair of tongs and press onto the sugared surface of your creme brulee. It looks almost like you’re branding it, as a burst of smoke rises up from the dessert, but in less than 5 seconds you’re left with a perfectly caramelized creme brulee.
Now, I don’t typically think of creme brulee as a barbecue dessert, but it actually goes quite well with a backyard cookout. The custards can be prepared well in advance and can be garnished with all kinds of fresh fruit. With one of these little gadgets, you can even prep them right outside in front of your guests and not have to spend any more time in the kitchen while you’re entertaining.