though you might feel compelled to send money to me, anyhow. Really, it is THAT wonderful that you'll feel an immediate rush of gratitude to the world... and to me. Ok. You CAN send me money. Or, more spinach.
Cook hamburger to desired level of doneness. Keep it pink if you like the thrill of a possible food borne illness.
Saute spinach in butter and onions.
Place burger in pan with the spinach and pile the spinach around burger.
Lift it out of the skillet as a unit.
Garnish as you like.
You might even want to consider wrapping it in bread or a nice bun.