In a large plate, add flour, salt, and pepper. Mix.
Pat the fish into the mixture on both sides.
Heat a large pan on med-high heat and once hot, add olive oil. Swirl pan to coat bottom.
Once oil is hot (a little bit of smoke starts to rise from the pan; happens quickly) add in the fish, two at a time or just enough not to crowd the fish.
Don’t move the fish around and just let cook for 1 minute. Flip the fish and cook for another minute. If your fish is thicker you’ll have to adjust the cook time accordingly.
Remove fish and place onto a new dish and repeat with remaining fish fillets.
Once you finished cooking all the fish, if your pan is cast iron you can take your pan off the heat now, otherwise turn your burner to low.
Add butter to melt and once melted, add lemon juice and parsley. Mix.
Add the fish back into the pan and serve. Enjoy this lovely thing!