In a bowl with high sides, combine all the sauce ingredients and blend with an immersion blender until smooth.

Transfer sauce into a small saucepan and simmer on low for 15-20 minutes until the sauce has thickened to a dipping consistency.

In a medium bowl, mix together all of the filling ingredients until fully incorporated. Place in the refrigerator until ready to use.

Line a large baking sheet with parchment paper and place a small bowl (around 4" in diameter) upside down on the baking sheet.

Taking 25g of perfect bun dough, flatten it out into a 2-3" circle. Take approximately 2 teaspoons of filling rolled into a ball and place the filling in the centre of the dough and fold the dough over the cheese. Pinch the bottom of the dough together completely so that the cheese is fully sealed inside your bun. 

Arrange filled buns around the bowl (seam side down) on the parchment lined baking sheet, starting with one inner circle and forming a second circle around it. Remove the bowl and cover the tray with a clean dish towel. Set in a warm draft-free area to rise until doubled, around 1-1 1/2 hours.

Preheat your oven to 375 F. Brush the top of each bun lightly with egg white and sprinkle with sea salt. Bake for 15-20 minutes or until the buns are golden brown.