With the oil, seer the pork fat until slightly brown over medium-high heat in a wok or a pan. Remove and set aside.
Then using the same wok or pan, flash fry the liver until outer part is cooked. Remove and set aside.
Sauté the onions until translucent, then add the garlic. Cook for 30 seconds.
Add the pork belly, stir until the meat is slightly brown over medium-high heat.
Add the potatoes and carrots. Stir until the vegetables sweat or roughly 1-2 minutes.
Add the hotdog, stir again for another minute.
Next add the tomato sauce, water, sugar, salt and pepper. Let it cook for 15 minutes.
After the first 15 minutes, add the bell peppers and liver. You may also add 1 cup of water again if the sauce has reduced to a low. Then let it cook for another 5 minutes.
Serve and enjoy! Menudo is best served over jasmine rice.