Score the pork roast with a sharp paring knife and make a crisscrossed line pattern across the pork. This provides more surface area for the smoke to adhere.
Peel the garlic cloves and stick them in each crisscrossed line intersection. You may need to slice the pork a little deeper here for the garlic to be fully inserted. As it cooks, the garlic will release its flavor throughout the roast and become soft.
Add salt and pepper the outside of the roast.
Preheat the grill to 250°F and set it up with indirect heat. For the Big Green Egg, I used a plate setter. For gas grills, turn off the center burners. For Kamado grills, add a ceramic or cast iron diverter.
Add the pork roast to the grill. You may want to add a drip pan under the pork, as the fat will render and create an unpleasant smoke.
Add your favorite wood chips. For a mild flavor, use a fruit wood. For a more robust flavor, try mesquite or hickory.
Let the pork roast smoke until the internal temperature reaches at least 145°F. I typically let it come up to 155°F and then remove it from the grill using meat claws, tent it in foil, and let it rest for about 10 minutes before slicing.
Notes
Let the Roast Rest - Take the roast off of the grill a few minutes before it reaches your desired temperature. Bring it inside and tent it in foil. The temperature will continue to rise for a few minutes and it will keep the juices locked inside.A Little Smoke Goes a Long Ways - You do not need (or want) big billowing smoke on the grill. It may look dramatic, but it can easily cause your food to taste like charcoal. Blech! Instead, a small, light trickle of smoke over the length of the cook will leave just the right amount of flavor. I always err on the side of too little, instead of too much.Storage - Sliced pork roast is fantastic for keeping in the freezer. I cut up any leftovers and add them to freezer bags or freezer-safe plastic containers with veggies and potatoes. They reheat easily and make for a fantastic lunch throughout the week.