Heat oven to 200°F, if you need to keep the quesadillas warm until you serve them. Whisk the eggs in a medium bowl with salt and pepper, and set aside. Place a medium cast iron or nonstick pan over medium heat and oil or spray lightly with olive oil. Pour the eggs into the pan and cook, stirring occasionally, until they are softly scrambled and still moist. Transfer to a medium bowl and stir in the pepper jack cheese. Divide the egg mixture into four portions.
Place a large skillet over medium-high heat for a few seconds. Carefully place a tortilla in the pan, then spoon one portion of the eggs onto half of the tortilla; sprinkle with a quarter of the arugula or spinach and a quarter of the avocado. Fold the tortilla over to cover the filling, place another tortilla on the empty side of the pan, and assemble the second quesadilla in the same way. Press lightly to seal the ingredients inside the tortillas. Using a spatula, turn the first quesadilla after about 2 minutes, being careful not to spill the filling. The tortilla should be browned and crisp. Repeat with the remaining tortillas and filling. Turn the heat down to medium if the tortillas are browning too quickly. Transfer the finished quesadillas to plates, cut each quesadilla in three wedges and serve with salsa.
Serve with a bowl of cut fresh fruit to add a sweet touch that balances the savory, spicy flavors of the quesadilla.
460 calories, 25 g. fat, 340 mg. cholesterol, 1000 mg. sodium, 34 g. carbohydrate, 6 g. fiber, 25 g. protein