Add flour, bread crumbs, celery salt and lemon pepper to large covered bowl or plastic food storage bag. Mix well.
Add smelts and shake until thoroughly covered. See notes below.
Melt butter in olive oil in large cast iron skillet over high heat.
Add smelts, in batches, to hot oil and saute 2-3 minutes per side, until browned and crispy. Drain on wire rack.
Serve with your favorite dipping sauce.
**Notes**Important to shake off excess flour!I find that shaking them in a bag introduces too much flour into the cavity that does not get cooked through and will make them taste like flour. If you choose to flour them in a bag, make sure to shake them off thoroughly.Good sauces for dipping;