Heat olive oil in a large skillet over medium heat. Add diced onion and cook until softened, about 3 minutes. Stir in minced garlic and cook for another minute.
Add ground beef to the skillet. Cook, breaking it apart with a spatula, until browned and fully cooked. Drain excess fat.
Stir in black beans, cumin, chili powder, smoked paprika, salt, and black pepper. Cook for another 2-3 minutes until well combined.
Warm the tortillas in a dry pan or over an open flame for a slight char.
Assemble the tacos by spooning the beef and black bean mixture into each tortilla. Top with cheese, salsa, avocado, and cilantro as desired.
Serve immediately and enjoy.