Add some oil to the skillet over medium heat. Once hot add the sausage and cook, stirring and breaking up the meat with a wooden spoon, until cooked through and crumbly, about 7 minutes.
Use a slotted spoon to remove the sausage from the pan to a paper-towel-lined sheet tray to drain off some of the grease.
To assemble the quesadillas, sprinkle each tortilla with 1/2 cup sausage, 1/2 cup cheese, some beans and Easy Homemade Salsa. Fold the tortilla over to close.
Heat a cast-iron double-burner griddle over medium-high heat. Add the butter and 1 tablespoon oil. Once the butter is melted and foamy, carefully add the quesadillas to the pan and cook on both sides until golden brown and cheese is fully melted, about 4 minutes per side. Serve with sour cream.
Easy Homemade Salsa:
Add the cilantro, tomatoes, garlic, jalapenos, lime juice, onion and some salt and pepper to the bowl of a food processor, and pulse until blended together. You want the salsa to still maintain some texture but be much smoother than if chopping by hand.