Heat the olive oil in a skillet over medium-low heat. Add the red onions and cook slowly for 10-15 minutes, stirring occasionally, until soft and deep golden brown. Set aside and cool.
Warm the tortillas on a grill pan or griddle over medium heat for 1 minute.
Divide hummus and spread down the middle of each tortilla. Arrange the cooked onion slices and sliced red peppers over the hummus.
Add the sliced artichoke hearts.
Toss the salad greens with the balsamic dressing, then add to the wrap.
Sprinkle crumbled feta over the greens. Tuck one side of the wrap and roll tightly to secure.