For small-batch brioche: Add the flour, salt, yeast, and sugar to the bowl of a stand mixer fitted with the dough hook, and mix together briefly to combine. Add the milk and 1 egg, and mix to form a shaggy dough.

On medium-low speed, knead the dough until smooth and elastic, about 10 minutes. With the mixer still running, add the butter 1 tablespoon at a time. Continue kneading until the dough is once again smooth and silky, up to 10 minutes more.

Turn the dough out onto the work surface, and form into a smooth round. Place the ball of dough into a lightly greased bowl, and cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, 45 minutes to 1 hour.

Line a large baking pan with a piece of parchment paper.

Lightly punch down the dough. Divide into 6 evenly sized pieces of dough, and roll each into a smooth round. Press each ball of dough into a 3-inch/7.5cm disc, and place on the baking pan. Cover and let rise in a warm, draft-free place (75°F/24°C) until doubled in size, about 45 minutes to 1 hour.

Preheat the oven to 390°F (200°C).

Brush each bun with beaten egg. Bake the buns for 10 to 12 minutes or until they are golden brown. Remove and set aside until fully cooled.

Using a chopstick, poke a hole in the top of the buns, wiggling around slightly to make a little room for the filling. Scrape the lemon curd into a piping bag fitted with a small round piping tip, and pipe about 1 tablespoon (20 grams) curd into each bun.

For lemon icing: Add all the ingredients except the lemon zest to a bowl, and beat together until smooth. Spoon a little icing onto each bun, and spread on the top of the buns, finishing with a light sprinkling of lemon zest. Best served the day they’re baked.