Preheat the oven to 400ºF. Place the whole red bell pepper on a small baking sheet and roast until soft, about 20 minutes. Set it aside to cool slightly.

While the pepper roasts, in a medium sauté pan, heat a drizzle of olive oil over high heat. Add the corn and cook until charred, 3-5 minutes.

Once the bell pepper is cooled, remove the stem and core, then cut the pepper into even strips. Remove the pits and skin from the avocados. Thinly slice 1 avocado.

Working 1 at a time, place a flour tortilla in a large sauté pan over medium-low heat. To 1 side of the tortilla, add the ¼ each of the bell pepper strips, charred corn, avocado slices, and cheese. Fold over the tortilla and cook until the tortilla is evenly browned and the cheese is melted, 2-3 minutes per side. Repeat with the remaining tortillas and filling ingredients.

In a blender, combine the sour cream, cilantro, lime juice, remaining avocado, and salt to taste. Blend into a smooth mousse and serve with the quesadillas.