Heat a large skillet over medium-high heat. Add the ground beef and cook, breaking it up with a wooden spoon, until no pink remains, about 6-8 minutes. Drain excess fat if needed, leaving about 1 tablespoon in the pan.

Push the beef to the edges of the pan, add the diced onion to the center, and cook until softened and translucent, about 3 minutes. Stir in the garlic and cook until fragrant, about 30 seconds.

Sprinkle the chili powder, cumin, smoked paprika, oregano, salt, and pepper evenly over the meat. Stir constantly for 1 minute to toast the spices and coat every bit of meat - you'll smell the difference when the spices wake up.

Stir in the tomato paste until fully incorporated, about 1 minute. Pour in the beef broth, scraping up any browned bits from the bottom of the pan. Reduce heat to medium-low and simmer until the liquid reduces and the meat is moist but not soupy, about 5-7 minutes.

Remove from heat and stir in the fresh lime juice. Taste and adjust salt if needed. The meat should be deeply flavored, slightly saucy, and glistening. Serve immediately in warm tortillas with your favorite toppings.