Step 1

Heat a large skillet over medium-high heat. While the skillet is heating up, pat steak dry on both sides with paper towels.

Step 2

In a small bowl, combine salt, onion powder, black pepper, cumin, and garlic powder.

Step 3

Sprinkle the seasoning evenly over both sides of the steak.

Step 4

Add 1 1/2 tablespoons of olive oil to the skillet and add the steak. Cook on each side for about 4-8 minutes, depending on how thick the steak is and how “done” you want it to be.

Step 5

Remove the steak from the skillet and transfer it to a cutting board to let it rest.

Step 6

While the meat is resting, add the remaining 1/2 tablespoon of olive oil to the skillet. Add the sliced onions and cook, stirring occasionally, for about 8 minutes, until softened.

Step 7

Transfer the onions to a bowl and carefully wipe off the inside of the skillet with a few paper towels until clean. Set aside.

Step 8

Uncover the steak and slice it against the grain at an angle into thin slices or into bite-sized chunks.

Step 9

In a medium bowl, combine the shredded mozzarella and monterey jack cheeses.

Step 10

Assemble the quesadillas by adding 1/2 cup of shredded cheese to the bottom of one tortilla, followed by some steak, then onions, and one more 1/2 cup of shredded cheese. Sprinkle a pinch of salt and then top everything with one more tortilla.

Step 11

Place the clean skillet back on the stove over medium heat. Using a spatula, carefully transfer the quesadilla to the skillet.

Step 12

Cook the quesadillas for 1-2 minutes, or until the bottom of the quesadilla is golden-brown. Quickly flip over the quesadilla and cook for another 1-2 minutes, until golden-brown and the cheese has fully melted.

Step 13

Assemble and cook the remaining quesadillas.

Step 14

Serve immediately as is, or cut the quesadillas into fourths. Serve with salsa, guacamole, and sour cream.