Cheese cubes work well as hors d'oeuvre. They're cut from harder cheeses, such as cheddar and Swiss, so they're easy to grab with a toothpick. But some people may not have use for them beyond a cocktail party. If you ordered or made a cubed cheese platter and have leftovers, you can melt them to make dips and sauces. For food safety purposes, after the party, transfer the cheese cubs from the serving platter to resealable bags and place them in the refrigerator until you're ready to use them.
Cut up the cheese cubes into smaller, uniform-size pieces. Following the culinary concept that food that's cut the same cooks the same, cheese into smaller pieces that are the same size all melts at the same pace. You also can grate the cubes -- the most efficient way to melt cheese -- if you have a grater, although grating individual cubes can be tedious and time consuming.
Add water to bottom part of your double boiler. Bring the water to a boil over high heat, then turn the heat down to medium; this keeps the water from boiling off too fast. Place the cheese cubes, or shredded cheese, in the top part of the double boiler and set it down over the hot water.
Stir the cheese cubes continuously as they melt. If the melted cheese is too thick for your purposes -- for example, if you're making a cheese sauce for baked potatoes or broccoli -- pour in a bit of milk or cream and mix it in well. You also can add diced tomato, onion and chopped herbs, like cilantro, to the cheese if you're making a dip for chips or vegetables.
Transfer the melted cheese to a bowl with a rubber spatula and serve it warm. Add salt and a pinch of cayenne or black pepper to taste. You can reheat the cheese in the microwave for a few seconds should it start to solidify.