Heat a skillet. 30 cm (12 inches) will be a good size to work comfortably.
Add a small piece of butter or oil of your choice. The butter/oil should barely cover the skillet. Heat over medium-low heat.
Add the tortilla on the skillet and on half of it put layers of goodies as per recipe.
Start with grated cheese. Then spread some mashed and spiced potatoes. Add cooked ground beef (skip if you want to make it a vegetarian quesadilla). Add chopped spinach. Cover with cheese.
Flip over the empty half, press down lightly. Check the bottom if golden and crispy flip to the other side. Make sure the stuffing does not fall out, stick back in if necessary.
When you notice that the cheese has melted and both sides are golden brown your quesadillas are ready.
Cut into half or wedges. Serve immediately and enjoy.