Warm the milk. Dissolve the yeast in the milk and let it rest for 5 minutes, then mix well. Add the sugar and salt to the milk-yeast mixture and whisk.
Place the flour in the bowl of a stand mixer with a dough hook attachment and knead at low speed while adding the milk mixture. Lightly beat 2 eggs and add them to the dough, kneading for 1 minute. Increase the speed and knead for 10 minutes until the dough pulls away from the sides of the bowl.
Meanwhile, cut the butter into pieces. Continue kneading while gradually adding the butter, and knead for another 7 minutes until the dough is elastic and shiny. Transfer the dough to a mixing bowl. Cover with a clean cloth and let the dough rise for 2 hours in an oven preheated to 122°F (50°C), then turned off with the door closed.
Divide the dough into 10 balls and soften each one on a floured surface. Roll them out on a floured surface into large strips. Spread a very thin layer of lemon curd over each strip and sprinkle with chocolate chips, reserving some for decoration. Roll them into spirals.
Place the spirals upright, side by side, in a greased rectangular pan. Cover with a clean, damp cloth and let the dough rise again for 1 hour as before. Remove the dough from the oven.
Preheat the oven to 350°F (180°C). Whisk the remaining egg with the remaining lemon curd and brush it over the brioche. Sprinkle with the reserved chocolate chips. Bake for 40 minutes until the brioche is golden brown. Allow it to cool before serving.