Melt butter in a small saucepan over medium heat, add the flour. Mix well and add milk. Bring to a boil and add the seasonings with salt. Reduce heat and continue to cook until thick.
Pour the salmon fillets with lemon juice, then season with salt and pepper. Fry the fish with olive oil on both sides for about 5 minutes until fork-tender. Pour fried fish with the sauce and serve. Enjoy your meal!!!