Heat skillet on high. When hot, add 1 Tbsp olive oil. Lay fish skin side down. With spatula, press fish into pan for 15-20 seconds, to sear bottom and avoid edge curling.
Reduce heat to medium/low and allow fillets to cook for 2-4 minutes (depending on thickness of fillet), letting the edges caramelize. Flip fillets, add 2 Tbsp butter and 1 sprig of thyme. Allow butter to melt, but not burn. Tilt pan and spoon butter onto fillets. Continue cooking and basting fillets with butter for 1-2 minutes. Remove fillets when fully cooked, and garnish with fresh thyme and fresh lemon juice.
The perfectly crispy skin complements the tender fillet perfectly.
Remove excess oil before cooking next pair of fillets.