In a large skillet, roast the tomatoes.
Add the dried ancho chile.
Toast for 1 minute on each side.
If the chile burns, the sauce will be bitter.
Continue roasting the tomatoes while you boil 4 cups of water.
Remove the stems and open up the anchos to remove the seeds.
Discard the stems and the seeds.
Place the anchos inside the boiling water.
Turn the heat off and let them sit in the hot water for 5 minutes, or until pliable.
Roast the tomatoes on all sides.
Add the onion, garlic, and bread to the skillet.
Char all the sides of the onions as well.
Remove the garlic and bread once toasted.
Remove the onions and tomatoes once they are ready.
Discard the water from the dried chiles.
Place the rehydrated dried chiles, tomatoes, onion, garlic, and bread into a blender.
Add 1 cup of water.
Blend until smooth.
Heat the olive oil in a stock pot.
Place a strainer over the top of the stock pot.
Carefully and slowly strain the mole sauce into the stock pot.
Add the chicken broth and Mexican chocolate tablet.
Stir until the chocolate has melted.
Taste it. If you want it sweeter, add 1 tablespoon sugar.