In a large bowl, whisk together the eggs, milk, melted butter, flour, salt and pepper. Whisk until all of the lumps have dissappeared. Whisk in the cheese and the thyme. Transfer the batter to an airtight container. The batter must be chilled; refrigerate for at least two hours or overnight. Preheat the oven to 425 degrees. Spray non-sitck spray in to cups of mini-muffin pan. Fill each cup to the top with the chilled batter. Bake the popovers until golden and puffed, fifteen to eighteen minutes. Serve warm.