In a small glass bowl, combine the diced Roma tomato, finely diced red onion, chopped cilantro, and lime juice to create the fresh salsa.
In a separate mixing bowl, toss the raw ground beef with chili powder, cumin, garlic powder, sea salt, and black pepper until the seasoning is evenly distributed.
Heat the olive oil in a medium stainless steel or cast iron skillet over medium-high heat.
Add the seasoned beef to the skillet, breaking it apart with a spatula, and cook for 5-7 minutes until browned and fully cooked through.
While the beef is browning, lightly toast the corn tortillas in a dry pan or directly over a low gas flame for 30 seconds per side until warm and pliable.
Slice the avocado into thin wedges.
Assemble the tacos by dividing the savory ground beef between the two tortillas.
Top each taco with a generous portion of the fresh salsa, avocado slices, and a dollop of Greek yogurt as a high-protein alternative to sour cream.