Italian Sausage Quesadillas

olive oil

One-half of a large onion, diced

minced garlic, or more to taste

hot Italian sausages, casings removed

tortillas (I used 8" flour)

fresh basil leaves, roughly chopped (about 1/4 cup chopped)

sliced roasted red peppers

shredded mozzarella cheese

Marinara sauce, for serving.