I have become an unabashed fan of the overstuffed tortilla. Those slight little triangles with only a smattering of cheese and a sprinkling of filling are not for me. Give me a quesadilla with height and weight over a delicate wedge any day. These are jammed with a medley of vegetables and a generous amount of shredded chicken (which you can get by cooking and shredding your own chicken breasts, or taking a supermarket rotisserie and tearing it up with your hands), and then it’s all bound together with a pile of cheese. And that’s before we get to the toppings: guacamole, sour cream, and salsa. —Katie Workman
Heat a large skillet over medium-high heat and add the vegetable or olive oil. Add the onion and broccoli, season with salt and pepper, and sauté for 3 minutes until the vegetables start to soften. Add the spinach, garlic, and chili powder and stir for another minute until you can smell the garlic, the spinach is wilted, and everything is well combined. Stir in the cilantro if using, turn the mixture into a bowl, and stir in the chicken until everything is blended.
Wash and dry the skillet (or grab a new skillet). Place the skillet over medium heat and add a half teaspoon of butter. Place a tortilla in the pan. Sprinkle 2 tablespoons of the cheese mixture over half of the quesadilla, and distribute 1/8 of the chicken and vegetable mixture over the cheese. Top that with another 2 tablespoons of the shredded cheese. Flip the bare half of the tortilla over the filling, cover the pan, and sauté for about 2 minutes until the bottom is golden and the cheese has started to melt, then use a spatula to flip the half-moon quesadilla. Continue to cook, uncovered, until all of the cheese is melted and the underside is browned, 2 to 3 minutes. You can cook two at a time, if you nestle them in the pan with the flat sides of the half moons abutting each other.
Remove the quesadilla to a cutting board and let it sit for a minute before you slice into 2 or 3 wedges. Repeat until all of the quesadillas are cooked. Serve with guacamole, salsa, and sour cream.