'1/2 cup finely chopped onion '
'2 tablespoons olive oil '
'2 tablespoons vinegar '
'1/2 tablespoon fresh thyme, minced '
'400 g ground pork '
'5 hamburger buns, crumbled '
'Salt to taste '
'For spreading '
'Butter '
'Optional '
'Cookie cutter with 8 cm diameter'
'1/2 cup finely chopped onion '
'2 tablespoons olive oil '
'2 tablespoons vinegar '
'1/2 tablespoon fresh thyme, minced '
'400 g ground pork '
'5 hamburger buns, crumbled '
'Salt to taste '
'For spreading '
'Butter '
'Optional '
'Cookie cutter with 8 cm diameter'
Season the pork with vinegar and salt
Over medium heat, sauté the thyme and onion in olive oil, stirring occasionally until the onion is soft
Add the ground pork and cook for 3 minutes
Place it in a bowl
Combine the crumbled buns and mix well to obtain a uniform mixture
Divide into six portions
Assemble by spreading butter on a flat surface and placing one-sixth of the mixture inside, pressing down
Repeat with the remaining portions
Heat a large skillet or frying pan over high heat
Brush it lightly with butter and reduce the heat to medium
Fry the hamburgers for 2 minutes per side or until golden brown
Place them on a platter and serve immediately.