Heat a medium cast-iron pan, add ground beef, cook and mash that, stirring occasionally for four minutes or until the meat has rendered all of its fat and is fully cooked.
Add garlic, jalapeno, onion, and season it with salt and pepper to taste; saute until all the vegetables have softened and start to caramelize, about 3 minutes.
Sauce: In a small bowl, mix sour cream, salsa verde, cilantro, and season to taste with salt.
In a medium bowl, mix Monterey Cheese and Cheddar cheese.
Assembly: On one of your homemade tortillas, add a couple of spoons full of your salsa-crema on one side, and spread it around on just half. Then add a small layer of cheese, followed by a layer of your beef mixture and another layer of cheese.
Fold it into a half-moon, add butter to a nonstick pan, heat over medium heat; once melted, add your quesadilla and toast for about 2 minutes, flip and toast for another 2 minutes until all the cheese gets melted.