The "Lazy" way to make a delicious healthy treat with no work! To find some of the artisinal Greek products you'll need to make this, visit my online shop, where you'll discover a host of lovingly curated Greek ingredients.
Heat half the olive oil and sauté the onion, scallions or leek until soft and lightly golden. Add the spinach and cook until wilted. Remove the mixture with a slotted spoon and drain well in a colander. Cool.
Combine the spinach mixture with the fresh herbs. Season to taste with salt, pepper and nutmeg, Mix in the feta.
Spread the mixture onto 4 1/4-inch-thick slices of good bread. Place the remaining four slices of bread on top.
Heat a cast-iron or nonstick frying pan and add the butter or olive oil (you can use both. together). Add the sandwiches, one or two at a time, and cook over medium heat on until golden on one side. Flip carefully to cook on the other side, pressing down with a spatula. Cover the pan for a few minutes to help the feta melt more easily. Repeat with remaining sandwiches, replenishing the olive oil and/or butter as needed.