A quesadilla is pretty much a Mexican grilled cheese. Take a tortilla, stuff it with something savory, add cheese, fold it in half and toast it.

But I was sure I could dream up a lighter version. I quickly discovered that it doesn’t take a ton of cheese to flavor the fillings of a quesadilla, as long as it’s full-fat cheese. I tried 4 ounces of reduced-fat cheese, but the flavor was so weak that my tasters didn’t know there was any cheese in the recipe. Using 2 ounces of full-fat sharp cheddar was a hit.

The rest of the filling is vegetables. I quickly cooked bell peppers and onions over medium-high heat until golden at the edges but still crunchy. I added mushrooms for flavor and bulk. Then I tossed in a jalapeno. You decide whether to add the seeds and ribs for a hotter dish. The cheese will tamp down some of the heat.

A cast-iron skillet is the perfect pan to cook this recipe. You also can grill the assembled quesadillas over low heat for a few minutes on each side.

Mushroom, Pepper and Onion Quesadillas

Ingredients

1 firm ripe avocado, diced

1 tablespoon lime juice

Kosher salt and ground black pepper

4 teaspoons vegetable oil, divided

1/2 cup chopped yellow onion

1/2 cup chopped red or green bell pepper (or a mix)

1 teaspoon minced garlic

11/2 cups assorted sliced mushrooms

1/2 fresh jalapeno, finely chopped (seeds and ribs discarded, if desired)

2 ounces coarsely grated sharp cheddar cheese

Four 8-inch flour tortillas, preferably whole wheat

Nonfat plain Greek yogurt

1/4 cup chopped fresh cilantro

Directions

Heat oven to 350. In a small bowl, toss the diced avocado with the lime juice and a bit of salt and pepper. Set aside.

In a large, preferably cast-iron skillet over medium-high, heat 2 teaspoons of the oil. Add the onion, bell pepper and a pinch of salt, then saute until golden at the edges, about 5 minutes. Add the garlic and cook, stirring, for 30 seconds. Transfer the mixture to a bowl.

Add remaining 2 teaspoons of oil to the skillet along with the mushrooms and a pinch of salt. Reduce heat to medium and saute until the liquid the mushrooms give off has evaporated, about 7 minutes. Transfer the mushrooms to the bowl with the onions and peppers. Add to it the jalapeno, cheese and a bit of salt and pepper. Mix well.

Wipe out the skillet and coat it with cooking spray.

Set 2 of the tortillas flat on the counter. Divide the onion-pepper mixture between them, spreading it evenly over each. Press a second tortilla firmly over each.

Heat skillet over medium. Add one quesadilla and toast until golden, about 2 minutes per side. Transfer to a baking sheet. Repeat with the second quesadilla. Bake for 5 minutes, or until just heated through. Cut each quesadilla into quarters, then divide between 4 serving plates. Top each serving with more avocado, yogurt and cilantro.