Cut walleye filets in portions that will 1) cook evenly and 2) fit in your selected tortilla. Dust the fish with equal parts flour and blackened seasoning. This is a great, light alternative to traditionally breading walleye that seems to be the preferred Midwest preparation.
Add butter to a skillet and melt over medium heat. Too much heat will burn or brown the butter.
Add pieces of fish, don't overcrowd the skillet. Depending on the size of your filets, the fish will cook quickly. When lightly browned on one side, carefully flip and season with a liberal pinch of salt. Total cook time will be around 3-4 minutes per side.
Set aside the cooked fish on a wire rack, repeat until all the fish has been cooked.
Salsa: You can prepare the day before or quickly toss it together moments before serving.
Dices jalapeños, half an onion and peaches into 1/4 cubes. Squeeze the juice of three limes over it. Add salt to taste -- depends how sweet your peaches are.
Warm your tortillas, place a piece of fish and dress with peach salsa. Simple preparation that lets the ingredients shine.