Make the dough

• Warm the milk slightly, then stir in the yeast and sugar and let it sit a few minutes.
• In a large bowl, combine the flour and salt, then pour in the milk mixture.
• Add the softened butter and knead until you get a smooth, elastic dough.

Let the dough rise

• Cover the bowl and leave the dough to rise in a warm spot until doubled in size.

Cook the burger filling

• Brown the ground beef in a pan over medium-high heat, breaking it up as it cooks.
• Add the chopped onion and cook until softened and the beef is fully cooked.
• Season to taste, then set the filling aside to cool slightly.

Fill and shape the buns

• Punch down the dough and divide it into 8 equal pieces.
• Flatten each piece into a disc, add a spoonful of beef filling and some grated cheddar in the center.
• Pinch the edges together to seal the filling inside, then roll each one into a smooth ball.
• Place the stuffed buns seam-side down on a lined baking tray.

Second rise

• Cover the buns and let them proof again until puffy.

Bake

• Preheat the oven to 180 °C.
• Brush the buns with beaten egg for a golden shine.
• Bake until deep golden brown and cooked through.