Trim the spinach, discarding any tough stalks. Rinse and drain well.
Melt some butter in a pan. How much depends on the amount of spinach you’re cooking. Just eyeball it. Spinach wilts so much and even if it looks like you have a lot, by the end of cooking time, you’ll end up with a very modestly sized side dish so go easy on the butter.
Saute some chopped garlic (again, how much is relative) in the butter. Add the spinach. Sprinkle with salt and pepper. Cook, stirring lightly, until the spinach is wilted.
Serve with grilled meat or seafood.