Season the pork heavily on both sides with the garlic powder, salt, and pepper. Transfer the seasoned pork to a heavy Dutch oven, making sure the pan is small, so the pork fits snugly, which will prevent the meat from drying out when it cooks. Add Coca-Cola and water. Bring to a boil and decrease the heat to maintain a simmer. Add the bay leaves, thyme, and tarragon. Cover and simmer until the pork is tender, about 1 ½ hours. The Coca-Cola will caramelize and the liquid will evaporate when finished.
Transfer the cooked pork to a cutting board, and using two forks, shred the meat into 2-inch long pieces.
Serve with the warmed corn tortillas, chopped onion, chopped cilantro, sliced radishes, lime wedges, and salsa.
The nutrition facts do not include tortillas or optional toppings.