Place the butter or olive oil in a large skillet and heat over medium heat, until the butter is melted (if using).
Add the garlic and the shallots or onions, if using, and sauté for 1 minute until golden. Season with salt and pepper.
Add the spinach in batches if necessary, and stir until it is wilted, about 4 minutes in total. Check and adjust seasonings as needed. Turn into a serving dish.
Notes
How Much Spinach Cooks Down
5 ounces of raw spinach (the size of a typical container or “clamshell” of baby spinach) yields about 1/2 cup of cooked spinach
8 ounces1/2 pound) spinach equals about 2/3 cup
1 pound of uncooked spinach will get you about 1 1/3 cups cooked spinach
More Tips
For 8 ounces of raw spinach, use about 1 teaspoon minced garlic
My favorite is sautéed spinach with garlic, but I also love adding in some leeks, shallots, or onions for additional depth of flavor and sweetness.
You can add a tablespoon of water if the spinach seems to be sticking at all to the pan or if you just want to make the cooking go faster.
I like using a combo of olive oil and butter for maximum flavor.