1. Heat 1 tablespoon oil in a large saucepan over medium heat. Add the onion and Serrano chile and cook, stirring occasionally, until softened, 5 to 8 minutes. 

2. Peel and dice one of the pears. Add the potato and diced pear to the skillet and continue to cook until the pear is softened and beginning to break down, about 5 minutes. Use a bean masher or potato masher to mash the mixture until fully incorporated. Add salt and pepper to taste. 

3. Wrap the stack of tortillas in a damp paper towel and warm in the microwave until softened, about 1 minute.

4. Spoon some of the pear mixture into the center of a tortilla and roll it up, leaving the ends open. Secure the roll with a toothpick. Repeat with the remaining tortillas and pear mixture.  

5. Wipe out the saucepan. Heat 1 ½ inches oil in the saucepan over medium-high heat. Working in batches if necessary to avoid crowding the pan, add the flautas and cook until golden and crisp, 3 to 5 minutes per side. Remove the toothpicks.

6. Dice the second pear. Serve the flautas topped with lettuce, sour cream, panela cheese, salsa verde and pear.