Heat the olive oil in a small saucepan and sauté the onion and red pepper. Stir constantly for around 5 minutes.
Add the black beans, corn, taco seasoning, salt and pepper. Cook over low heat for around 7 minutes, stirring every now and then. Put aside.
Heat ½ a spoon of butter in a non-stick pan. Once melted, add a tortilla. On one side of the tortilla, add a layer of cheese, a layer of beans and a final layer of cheese.
Fold the tortilla in half and turn down the heat. Cook for around 3 minutes, then flip onto the other side until it browns. Repeat for each tortilla. Serve with sour cream and finely chopped spring onion. Enjoy!