Place the spinach leaves in a very large, deep skillet. Add ¼ cup of water.
Cover tightly (ideally with a clear lid so you can peek) and turn the heat to medium-high. When the spinach starts to steam, turn the heat to medium, and gently steam until the leaves are just wilted, 3-5 minutes.
Transfer the cooked spinach to a colander. Press on it with the back of a large serving spoon to extract as much liquid as you can.
Transfer the steamed spinach to a serving plate. Sprinkle with salt, pepper and garlic powder, and drizzle with melted butter and lemon juice. Mix and serve.
Make sure the lid fits tightly over the skillet. Otherwise, the water will evaporate, leaving the spinach dry and even burnt.