Preheat oven to 400ºF. Set up 3 plates on the counter; in one spread the flour, in the second beat the eggs with the mustard and about 2 tablespoons of flour, in the third combine the breadcrumbs, cheese and some salt and pepper.
Coat the peppers in the flour, then in egg and finally in the breadcrumbs, pressing to make sure coating sticks. Roast peppers in the oven, turning halfway through baking until golden brown and crispy, about 18 minutes.
For the Ranch dipper: In a medium-size bowl, mix together the buttermilk, sour cream, white wine vinegar, garlic, hot sauce, parsley, dill and chives. Season with salt and freshly ground black pepper.