Season salmon around with salt & pepper. In a large bowl, blend together cream-cheese, mozzarella, garlic, garlic-powder, and red-pepper flakes.
With a paring knife, then slit a slit in every salmon to make a pocket. Materials pockets with cream-cheese mix.
In a skillet over moderate heat, warm oil. Insert salmon skin side down and cook until seared, about half an hour, then reverse salmon. Add butter and squeeze lemon-juice over. Cook until the skin is crispy, just another 6minutes. Serve warm.