Brown ground beef. Season with taco seasoning, stir, then drain and set aside.
Lay tortilla flat, fold in half, open back up, then fold in half opposite direction, and open up again. The fold marks create a center point and 4 equal quadrants. Cut along one line going from the center of the tortilla to the right edge. Top right quadrant is for the sour cream (spread evenly), bottom right - single layer of ground beef, bottom left - single layer of shredded cheese, top left - single layer of pico de gallo. (The cut is between the sour cream and ground beef.)
Take the top right sour cream section and fold it over onto the top left pico de gallo section. Then continue by folding that section down onto the bottom left cheese section and again onto the bottom right, until it is a multi-layer triangle.
Preheat air fryer, if possible. Place folded quesadillas into the air fryer, without touching each other. Air fry at 380°F for 4-5 minutes, until golden brown and crisp on the outside. Serve immediately.
Stove Top Instructions: Heat a skillet over medium-high heat. Add 1 tablespoon cooking oil to the skillet or spray pan with cooking oil. Place folded quesadillas in the pan and cook for about 3 minutes per side.