Heat your skillet over medium-high heat and add the ground beef. Break it up as it cooks, pressing it against the pan to get it browned nicely. This takes about 4 minutes total. You want the beef to look brown and slightly crispy, not gray and steamed. Don't skip this step — it's where all the flavor happens.

Once the beef is browned, push it to the side of the pan and add your diced onion and bell pepper to the empty space. Let them cook for about 2 minutes without stirring. This gives them a slight char and keeps them from getting mushy. Then stir everything together and cook for another minute.

Add the minced garlic and cook for about 30 seconds until you smell it getting fragrant. That's your signal not to burn it. Immediately add the chili powder and cumin. Stir everything together and let it cook for another 30 seconds so the spices release their oils.

Pour your salsa into the beef mixture and stir it all together. Let it cook for about 1 minute so the salsa reduces slightly and the filling gets thicker. This is crucial — if your filling is too wet, your quesadillas will be soggy. If it looks soupy, let it cook another 30 seconds.

Remove the beef mixture from heat and stir in the lime juice. Taste it and add salt and pepper as needed. Set it aside to cool for just a minute. You want it warm but not hot enough to melt the cheese before the tortilla hits the pan.

Heat a clean skillet over medium-high heat. You don't need to add oil to this pan yet. Place one tortilla on the hot surface and let it warm for about 15 seconds. This helps it become pliable without getting oily.

Flip the tortilla and immediately add 1/4 cup of the beef mixture to one half. Sprinkle about 1/4 cup of cheese on top of the beef. Fold the tortilla in half and press down gently with your spatula.

Cook for about 45 seconds on the first side until you see the tortilla start to turn golden and crispy. You'll notice the edges getting darker. That's exactly what you want. Flip it carefully and cook the other side for another 45 seconds until it's golden brown and crispy all over.

Transfer your finished quesadilla to a cutting board and repeat with the remaining tortillas and filling. You should have 4 quesadillas total. Let them rest for about 1 minute before cutting. This lets the cheese set up so it doesn't pour out everywhere.

Cut each quesadilla into 4 triangles and serve immediately. Serve with the Greek yogurt mixed with a bit more lime juice as a cooling dipping sauce.