While the bottom crusts are cooking, brown the ground beef in a skillet until no longer pink. Drain any excess grease.
Add the spices, 1/4 cup of water, and the black beans (drained) to the skillet and mix well. Allow that to saute for 5-10 minutes.
Beat 8 eggs in a large bowl and mix with the milk (optional).
When the bottom crusts are done baking, remove them from the oven and add half of the ground beef and bean mixture to each crust.
Now pour half of the egg mixture over meat and beans in each pan.
Return both pans to the oven and bake for 20-30 minutes or until the eggs are set. If you are only doing one quiche, it will take less time. Two quiches will take more time. The type of pan you use will also make some difference.
OPTIONAL: You can top the quiche with shredded cheese after the eggs are mostly set and let it melt during the final minutes of baking.
Cut into 8 pieces and serve with your favorite taco toppings such as guacamole, avocado slices, salsa, cholula hot sauce, sour cream, and cheese.