Note
1. In a large metal mixing bowl, add the water, flour, yeast, and oil.
2. Warm the chocolate baking bar in the microwave until it has completely melted (about a minute) or use a double boiler (bring an inch of water to a boil in a saucepan, then place a heat-safe bowl on top, add the chocolate and melt it, mixing frequently, about 2 to 3 minutes).
3. Meanwhile, add the salt to the dough in a large mixing bowl, turning it over in the bowl and kneading it until the salt disappears (about a minute).
4. Begin the final 10-minute hand mix.
5. Cut the dough into 2 or 3 even pieces (depending on your preferred size), weigh and ball.
6. Place the balls in a proofing container (or in lightly oiled containers covered with plastic wrap or lids) and cold-ferment in the fridge for 48 hours.