Begin by making the Pulled Pork: Preheat the oven to 300 degrees.
At the bottom of a large Dutch oven, place the onions. Mix all the spices together and rub them all over the pork. Place the pork butt on top of the onions, fat side up. Add the chicken stock to the bottom of the pot.
Bake, tightly covered, for five hours. When the pork is done, shred it with two forks and stir in the sugar. You'll only need about a quarter of the pork for this recipe. Freeze the rest for other meals.
While the pork cooks, make the barbecue sauce and the cheese sauce. And, fry the tater tots, right before serving.
For the Bourbon Barbecue Sauce: Melt the butter in a three quart saucepan, and cook the onion and garlic until softened. Then, add the rest of the ingredients, and simmer uncovered for 20 minutes. Stir this into the pork you're using to top the tater tots.
For the Cheese Sauce: In a small bowl, toss together the cheese and the cornstarch. In a three quart saucepan, bring the milk to a simmer. Turn the heat to low and whisk in the cheese. Whisk until the sauce thickens. Pour it into a bowl. You can reheat it in the microwave for a minute right before serving.
For the Homemade Tater Tots: Bring a three quart saucepan, half full of water, to a boil. Add a tablespoon of kosher salt and the potatoes. Boil them for ten minutes. Drain them and let them cool, until they're no longer hot. Shred the potatoes on the small holes, and put them into a bowl. Add the onion, garlic, thyme, salt, pepper, and flour. In a Dutch oven, bring an inch of oil to 350 degrees. While the oil heats, roll the potato mixture into one inch balls. It helps to oil your fingers while doing this. Fry the potatoes in four batches, dropping them in one at a time. Fry each batch until they're golden brown, for about three minutes. Don't add another batch until the oil goes back to 350 degrees. Drain the tots on a wire rack over a pan. These can be made ahead and reheated in an air fryer.
Place your tots on a serving platter, and top them with the pork, cheese sauce, scallions, cilantro, and tomatoes.