Heat olive oil in skillet over medium high heat
Add peppers and corn and cook until slightly softened, about 4-6 minutes
Add chicken and black beans to skillet with veggies
Stir in seasoning, cilantro and just enough water to combine
Let simmer until heated through
Remove from heat and let cool slightly
Assemble by placing a layer of cheese on one tortilla
Top the cheese with 1/4 of the filling mix and more cheese
Finish off with an additional tortilla
Melt butter in clean skillet
Carefully add quesadilla and cook for 2-3 minutes until lightly browned and cheese start to melt
Flip and finish on the other side
Repeat with remaining tortillas
Drizzle with ranch dressing or serve on the side as a dipping sauce