Heat the olive oil in a medium non-stick skillet over medium-high heat.
Add the ground beef to the skillet, breaking it apart with a wooden spoon. Cook until browned and no longer pink, about 5-7 minutes.
Stir in the chili powder, cumin, garlic powder, onion powder, sea salt, and black pepper. Cook for another 1-2 minutes until fragrant, then remove from heat.
In a small bowl, mash the avocado with the Greek yogurt, lime juice, and chopped cilantro until smooth and creamy.
Warm the corn tortillas in a dry pan over medium heat for 30 seconds per side until pliable.
Divide the seasoned beef between the two tortillas.
Top each taco with shredded romaine lettuce, diced tomatoes, and a generous dollop of the avocado crema.