To make chipotle sauce, whisk together butter, sour cream, ground chipotle pepper, cilantro and lime juice. Any leftovers should be stored in fridge.
Preheat grill to medium high heat.
Combine chopped red pepper, zucchini, corn kernels, scallions, olive oil, salt and pepper. Dump out onto large sheet of foil or flat pan designed to be placed directly on grill. Transfer to the grill and cook until veggies are tender and slightly charred, about 5 minutes, stirring frequently.
Serve immediately with tortillas, cilantro, cheese and chipotle sauce.