Breakfast Burrito

Name: Breakfast Burrito
Ingredients: 1 tablespoon extra-virgin olive oil; 1/4 cup finely chopped red onion; 4 slices of turkey bacon, cut crosswise into 1/2-inch strips; 2 packed cups baby spinach, coarsely chopped; 1/2 cup cherry tomatoes, thinly sliced; Kosher salt; 4 large eggs; 4 large egg whites; 1/4 cup crumbled feta cheese; 1 tablespoon snipped chives; Four 8-inch, whole-wheat tortillas, warmed; 4 red leaf lettuce leaves