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

Wash + dry parsley; remove stems + roughly chop; heat a skillet over med + add 2-4 tbsp butter; cook butter while stirring until browned, 2-3 min; cool butter slightly + add parsley, ½ squeezed lemon + salt/pep

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