Make Chipotle Sour Cream: In a small bowl, combine sour cream, chipotle pepper, adobo sauce and lime juice. Stir to combine. Add salt, to taste.
Make beans: Combine pinto beans, water, chili powder, cumin, dried oregano, and salt in a saucepan over medium heat. Bring to a boil, stirring often. Reduce heat as water starts to cook off and beans become creamy. Remove from heat. Using the back of a wooden spoon, slightly mash beans. (You want the beans to be spreadable - creamy but not wet.) Taste and adjust seasonings, as desired.
Build quesadillas: Place tortillas flat on a work surface. Spread equal amounts of beans on one half of tortilla. Follow with TomaRashi. Fold the opposite side of tortilla over on top of the beans and cheese to close. Continue until you've used up all your filling.
Place quesadillas in a large skillet over medium heat. (You might have to work in batches depending on the size of your skillet.) Carefully flip quesadillas every 2-3 minutes until cheese is melted and tortillas are evenly browned.
Serve quesadillas immediately with chipotle sour cream and garnish of your choice.
