Dice the pork into pieces about 2 and 1/2 inches in size.
Peel the onion and chop it up roughly.
Peel and slice the garlic.
Flavor all sides of the meat with salt and pepper equally, place it into the pan together with the garlic and the onion, and mix well.
Cover the pan either with a lid or aluminum foil.
Preheat the oven to 250 °F (120 °C) – roast slowly, but for a long time!
Roast the pork belly pieces for two and a half hours. There’s no need to stir it while in the oven.
Take the pan out of the oven, remove the lid (aluminum foil), and stir the meat and the veg gently.
Return it to the oven, this time without the lid. Turn the temperature up to 390 °F (200 °C) and roast for a further 30-40 minutes until all of the fluid evaporates, and only the fat remains. This way, the výpečky will be a nice golden brown in color, and its crust will be crumbly.
You have to mix the meat at least three times in this phase, mostly at the end, so that the výpečky won’t get stuck to the bottom of the pan.
Notes
Vepřové výpečky also taste great cold with a slice of fresh bread and pickles.