• In a skillet, melt butter over medium heat. Add onions and garlic and saute until onion is translucent, about 2 minutes. Set aside to cool.
• Place ground beef in a large mixing bowl.
• In a separate mixing bowl, mash black beans slightly. They should be smashed but still a little clumpy.
• Combine your spices in a small bowl, stirring to incorporate together.
• Add mashed beans to ground beef, and gently combine with your (washed) hands until incorporated.
• Add cooled onions and garlic and the spice mixture to the ground beef, and combine gently again with your hands until ground beef is coated and everything is combined.
• Divide the meat into 4-8 portions, depending on how big you'd like your burgers.
• Form each portion into a loose 3/4 inch patty, and indent the center of each burger with your thumb.

For Grilling

• Heat your grill to high heat.
• Lightly brush each burger with a little oil and cook on the grill for 3-5 minutes on the first side.
• Flip your burgers and cook for an additional 4-5 minutes, adding cheese for the last minute, if desired.

For a Skillet

• Heat about 2 tablespoons of oil in your skillet over high heat until the oil begins to simmer.
• Add burger patties and cook for 3-5 minutes on the first side.
• Flip your burgers and cook for an additional 4-5 minutes, adding cheese for the last minute, if desired.

To Assemble Burgers

• Place each patty between a bun, and dress it up like you would your favorite taco.