Quesadillas are hard to get wrong. They can be simple with just tortillas and cheese, or you can stuff them with all sorts of goodies.
When I make quesadillas, I like to use lots of ingredients: Tortillas, cheese, chicken, caramelized onion, roasted garlic, and BBQ sauce.
They can also be topped with salsa, pesto, or any number of taste amplifying sauces.
Using a panini press is the absolute best way to make quesadillas. Stovetop works decently, though microwave does in a pinch or if you want them nice and soft.
For an extra crispy crust, butter or oil work well, as does a small layer of shredded cheese on the outside. I add the tiny bit of cheese midway through cooking and it makes it nice and crisp.
Keto tortillas can be found (here) and at the store (carb balance)