Heat 2 teaspoons olive oil in a large sauté pan over medium heat.
Add the diced red bell pepper and diced white onion and cook, stirring occasionally, until the onion is translucent, about 4–6 minutes.
Add the minced garlic and cook for 1 minute more, then remove the pan from heat and transfer the vegetable mixture to a mixing bowl.
Stir the sliced black olives, roasted corn, and shredded chicken into the bowl with the vegetables until combined.
Place one flour tortilla in the sauté pan over medium heat. Spoon about one quarter of the chicken-and-vegetable mixture onto the tortilla, spread a small amount of the minced chipotle pepper evenly, then top with one quarter of the shredded Monterey Jack and a sprinkle of minced cilantro if using.
Top with a second tortilla and cook until the bottom tortilla is golden and the cheese begins to melt, about 2–3 minutes.
Carefully flip the quesadilla and cook the other side until browned and the filling is hot and the cheese is fully melted, about 2–3 minutes more.
Transfer to a plate and cut each quesadilla into quarters. Repeat to make the remaining quesadillas.
Serve warm with sour cream, salsa, or guacamole if desired.