These ingredients are traditionally ground by hand, though a blender works too; then they are roasted and combined with water and oils. This mixture is simmered for many hours while the final ingredients and salts are added. Each family and restaurant makes mole negro a little differently, and I think that is what makes this sauce extra special. Mole is never the same, each time you taste it.
Mole is connected to the local environment and culture through the ingredients used to prepare it. For example, chocolate, (aka the cacao plant) is Indigenous to this region, so it is known to have colored the culinary scene before the Spanish arrived. The other ingredients like herbs, nuts and seeds are also grown in the region. Many of these ingredients are also native to this land. Traditionally, people grind them by hand in a molcajete or on a flat stone to get the perfect consistency. I love watching this process because it's traditionally done in the Mexican kitchen, which is separate from the home, and part of it can be outside. Women will sit on little stools and grind these ingredients all day to prepare the perfect moles for their families. Many people boast that the traditional art and act of making mole is a way to show your family love.