We are hopping on board the hack train with a simple technique that will give you caramelized onions in 90 minutes of inactive cooking.
Use. Your. Grill.
Start by preparing your gas grill for "indirect cooking." Or, in Amy's terms, turn the front and back burners on medium heat and leave the middle one off.
Put whole onions, skin and all, in the middle, where the burners are off. This will create a type of convection-style cooking that will slow-roast your onions to deep, roasty, sweetly caramelized perfection in 90 minutes of inactive time. Yep! Just set a timer for 90 minutes and go do something else. No "stirring frequently" necessary.
When the timer goes off, you'll open your grill and find onions that are gorgeously brown and mushy. Unpeel them carefully, like Chris does here, using kitchen shears to snip off the top:
Squeeze them out of the skin, cut them to size, and use them in your favorite recipe, like French onion soup or an onion tart. Toss them in a salad. Use them as a pizza topping. Drape them on a burger. Pitch them into a pasta. Fold them into a frittata. We could go on, but we think you get it.
Caramelized onions - hacked!