Heat the oil in a non-stick pan over medium heat. Once hot, saute the onion and potato until the potato starts to become tender. Add in the sausage and saute until it is cooked through.
Preheat a panini style grill. Alternatively use the nonstick pan to cook the quesadilla.
Spread the cheese onto the tortilla and top with chorizo mixture then fold the tortilla in half.
Cook the quesadilla on both sides to golden brown and the cheese has melted.
Cut into wedges. Serve with sour cream. Garnish with cilantro.
Notes
Pro Tip - watch the heat, don't be afraid to use a lower temperature so that the outside gradually comes to a golden brown while the cheese is melting.