1Pat the beef dry with a paper towel and sprinkle with salt and pepper. Drizzle some oil into a large, heavy skillet (cast iron is ideal) set over medium-high heat. Brown the meat, getting some good colour on it - don't worry about cooking it completely through. (It is a steak, after all.) Transfer to a plate.
2Add the garlic and curry paste to the pan, then the peanut butter and coconut milk. Stir to blend and melt the peanut butter, scraping up any browned bits from the bottom of the pan.
3Cook for a minute or two, until well blended and thickened; return the beef to the pan and heat through, simmering a little longer if the beef is still too pink inside. Serve immediately, over rice.