Mince the onion, slice the shiso leaves, and thinly slice the garlic.

Heat 1 tbsp salad oil in a pan, fry garlic slices on low heat until golden brown, then remove. Add onion and sauté until translucent, then let cool.

In a bowl, soak breadcrumbs in milk. Add ground meat, salt, pepper, and nutmeg, then knead until sticky. Mix in the cooled onion, divide into two portions, and shape into patties with a slight indentation in the center.

Heat 1 tbsp salad oil in a pan, cook patties on medium heat until browned on both sides. Cover and cook on low heat for 7 minutes, then remove.

In the same pan, add sauce ingredients and simmer over medium heat until thickened.