Measure out all spices (cumin, chili powder, paprika, garlic powder, oregano, salt, black pepper, and cayenne pepper) into a small bowl and mix together. Dice the tomatoes and red onion into bite-sized pieces, and roughly chop the cilantro. Cut the lime into wedges. Having everything prepped before you start cooking ensures the beef won't overcook while you're scrambling to gather ingredients.

Heat the vegetable oil in a large skillet over medium-high heat. Once shimmering, add the ground beef and cook for 6-8 minutes, breaking it up with a spoon as it cooks, until no pink remains and the beef is nicely browned. This browning step develops rich flavor through caramelization—don't skip it by stirring constantly; let the beef sit for a minute or two between stirs to build color.

Add the spice mixture from Step 1 and the tomato paste to the browned beef. Stir well, coating all the meat evenly, and cook for about 1 minute until the spices become fragrant. Pour in the beef broth and simmer for 3-5 minutes until the liquid reduces slightly and the sauce thickens enough to coat the back of a spoon. I like to let it simmer gently rather than boil rapidly—this keeps the sauce rich and prevents the spices from tasting harsh.

While the sauce is simmering in Step 3, heat the flour tortillas. You can warm them directly over a gas flame for a few seconds per side (if you have a gas stove), or stack them on a damp paper towel and microwave for 30-45 seconds until pliable and warm. Warm tortillas are less likely to tear when filled and taste much better than cold ones.

Place a warm tortilla on your work surface and spoon a generous amount of the beef mixture from Step 3 down the center. Top with a handful of cheese blend, a pinch of the diced tomatoes from Step 1, a sprinkle of diced red onion, and a small pinch of cilantro. Squeeze a wedge of lime over the top. Repeat with the remaining tortillas until all beef is used.

Arrange the assembled tacos on a serving platter. Place small bowls of sour cream, guacamole, pico de gallo, and refried beans alongside for guests to add as desired. This lets everyone customize their taco to their preference and makes for a casual, interactive meal.