You can adjust the spiciness to some degree by using more or less chipotle peppers. For less spice, chop and measure one pepper (about 1 tbsp), then make up the remaining amount with adobo sauce only. For more spice, increase the chopped pepper ratio. If there isn’t enough adobo sauce in the can to reach the 6 tablespoons needed, substitute with ketchup, tomato puree, or more tomato paste.