Using the tip of a sharp paring knife, make 20 evenly spaced small slits about 1 1/2 inches deep all over the pot roast. Using your fingers, insert the garlic cloves as deep into the meat as possible.
Using a 1/4 teaspoon measuring spoon, spoon 1/4 teaspoon of the steak rub into each slit along with the garlic.
Heat a Dutch oven over high heat. Add the oil and, when hot, add the roast and sear until well browned on all sides, 4 to 6 minutes per side.
Add the stock, cover the pot, reduce the heat to low/medium-low and cook the roast until it is very tender, about 3 to 3 1/2 hours, turning 2 or 3 times while cooking. Check occasionally to make sure that there is always a little liquid on the bottom of the pan. If necessary, add more water or stock.
Serve immediately over cooked pasta, steamed white rice or creamy grits.