Drizzle sweet potato with olive oil. Season with salt & pepper. Arrange in an even layer on a baking sheet. Roast for 40-50 minutes.
Place a tortilla in pan over medium high heat and add a layer of cheese. Allow to melt for 1 to 2 minutes. Add sausage, sweet potato, red onion, and jalapeño.
Sprinkle on another layer of cheese and place a second tortilla on top. After about 5 minutes, carefully flip the quesadilla.
Allow it to brown for about 5 more minutes before slicing and serving. Top with scallions.
Recipe by Rachel Schultz at https://rachelschultz.com/2014/09/23/sausage-sweet-potato-quesadillas/