Heat the olive oil in a large skillet over medium-low heat. Add the garlic and cook for a minute or two to let the oil infuse with the garlic. Remove garlic and discard.

Add the spinach to the olive oil and cook until it is wilted down. Add in the nutmeg and season to taste with salt and pepper. When the spinach is wilted down, stir in the sour cream and the artichoke hearts.

Butter one side of each of the slices of bread. Place 4 slices, butter side down, on a griddle. Place 1/8 of a cup of the cheese on each slice. Divide the spinach mixture evenly between the 4 slices of bread, then top with an additional 1/8 cup of cheese. Place the remaining 4 slices of bread on top, butter side out.

Grill until golden brown on each side, about 3-5 minutes. Let cool for a couple of minutes before serving.