Turn on stove to medium-high heat.
Brown the pork - Drizzle some oil into the large pot, enough to coat the bottom, and toss in the pork butt chunks. Sautee it around and let it cook until golden brown. Keep lid on. (about 10 minutes)
Splash in the shaoxing wine. Scrape around the bottom with a wooden spoon to deglaze some of that browned burnt goodness from the pork. Let the wine evaporate (2-3 min.)
Toss in the chopped onions, garlic, and bay leaves. And pour in the soy sauce and worcestershire sauce, water, and sugar. Give it all a stir. Place lid back on to let simmer while you cut up your vegetables. (about 20 minutes)
Toss in carrots and tomatoes. Give the pot another stir to fold in the carrots and tomatoes. Place lid back on and let simmer on medium heat, stirring occasionally to make sure nothing burns on the bottom. (Simmer for about 1 hour)
Add potato chunks and stir into the rest of the pot. Taste if you'd need a little more of soy sauce, worcestershire, water or a dash of sugar. Now's your chance. If it's looking a little dry, add another 1/2 cup of water and add more soy sauce, sugar, and worcestershire to taste. There should be a nice saucy consistency. Place lid back on and continue to simmer on medium heat for another 30 - 45 minutes.
Simmer until pork is tender. Let it simmer for longer if you want the pork extra tender -- it's okay if some of the carrots and potatoes melt away. They all go into building the rich flavors of the broth.