Heat 1 tsp oil in skillet over med/high; pat both steaks dry, season with salt/pep + sear undisturbed 2-3 min, flip + cook 2-3 min for med-rare (for well done, add 1-2 min per side); cut steaks into ½-inch slices

Meanwhile, heat 1 tbsp oil in large skillet over med-high + sauté ½ of spinach + salt/pep 1-2 min; add the rest + cook 1-2 min more til wilted; set aside

Remove thyme leaves from stems; heat a skillet over med + add butter; cook butter while stirring until browned, 2-3 min; cool butter slightly + stir in thyme leaves

Divide steak + spinach between plates; drizzle brown butter sauce on steaks