Add spinach and water to a skillet set over medium heat. Cook, stirring occasionally, until the spinach is completely wilted. Drain excess water. Add the artichoke hearts, using a fork to break them up a little bit. Stir in a slice or two of cheese – just enough to melt into the vegetables and help bind them together.

Butter 4 slices of bread and sprinkle them with garlic powder. Flip two slices of bread over (so the non-buttered side is up) and top each with a few slices of cheese and half of the spinach and artichoke mixture. Cover with remaining cheese and top with a second piece of bread (buttered side up).

Cook sandwiches over low heat for 3 minutes on each side, or until bread is golden brown and cheese is melted.