Sift the flour into a large bowl. Add the yeast on one side of the bowl and the sugar and salt on the other side of the bowl. Using a whisk or fork, mix these ingredients together.
Pour warm milk and oil into the dry ingredients and mix to combine. Knead for about 4 minutes, until the dough is soft and smooth. Rub a little oil in the bowl and on the dough. Place the dough into the oiled bowl and cover with plastic wrap or a kitchen towel. Place the covered bowl in a warm, draft free area of your kitchen for 45 minutes to an hour.
After an hour, punch down the dough and roll into the shape of a log. Using a pizza cutter or sharp knife, cut the dough into approximately 10 pieces.
Shape each piece of dough into a ball. Using a rolling pin, roll out each piece of dough into roughly a 12 inch ( 30 cm ) circle. Brush the rolled out dough with melted butter and place onto a board or your countertop.
Roll out another piece of dough and stack it over the first rolled and brushed out circle.
Brush with butter and continue the process of rolling, brushing and stacking until all the pieces of dough are used. This is creating the beautiful flaky layers you will see when baked
Do not brush the top of the last circle of dough which you place on the stack.
Gently pull the top layer of dough over the edges of the stacked circles of dough.
Then roll out this entire stack of dough to about 14 to 15 inch ( 37 to 40 cm) large circle. Using a pizza cutter or very sharp knife, divide into 16 triangles.
Cut a small slit in the centre of each triangle base
Add your chocolate to the wide end then roll the dough up. Place, tip side down, on a tray lined with baking paper.
Repeat with the rest of the dough, spacing the croissants a few inches apart on the tray. Leave to rise on the tray for 15 minutes.
After 15 minutes, bake the croissants in a preheated oven of 356°F (180°C ) for 15 minutes.
Remove from the oven and brush with a sugar glaze or dust with powdered / icing sugar.