Heat a large skillet over medium heat and add the butter. When the butter is hot, stir in the corn and the starchy liquid scraped from the cobs. Cook for 5 minutes, then stir in the garlic and season with salt and pepper, to taste. Cook for 2 to 3 minutes more, then add the cream and nutmeg, stirring occasionally, until very creamy, about 15 minutes. Add the spinach and stir until wilted. Season with salt and pepper, if needed. Transfer to a serving bowl and serve.