One more thing: If the chocolate drops down below 88 degrees F and starts to set, you may need to warm it again just slightly. Otherwise, the peppermint bits will hit the hard surface and fall off rather than sticking as they should. If the mixture is still in the stirring bowl, simply return it to the microwave and nuke it 2 or 3 seconds, then stir thorough. If the mixture is already spread out in the baking sheets, warm it in a low oven for a minute or two–watch carefully as you want only the surface to be tacky, not the whole layer to melt.
About 1 pound 6 ounces semisweet or bittersweet (not unsweetened) chocolate or white chocolate, divided
1 tablespoon corn oil or other flavorless vegetable oil
2 to 3 drops oil of peppermint, optional
1/2 to 3/4 cup (about 4 1/2 to 5 ounces) crushed peppermint pinwheel hard candy or candy canes
Line a 10- by 15-inch (or similar) rimmed tray or baking sheet with aluminum foil; allow the foil to overlap on the narrow ends by 1 1/2 inches and try not to wrinkle the foil. Break up or chop 1 pound chocolate into small chunks; leave the remaining 6 ounces whole.
In a medium microwave-safe bowl, microwave the chopped chocolate and oil on 100-percent power for 1 minute. Stop and stir. Continue microwaving on 50 percent power, stopping and stirring every 30 seconds until most of the chocolate is melted. (Alternatively, heat the chopped chocolate and oil in a heavy, medium saucepan over lowest heat. Stir and watch carefully until most of the pieces are melted. Immediately remove the pan from the heat.
Transfer the chocolate to another dry, cool bowl. Continue stirring until the chocolate completely melts, about 5 minutes longer. Stir in the peppermint oil ( if using) and 4 ounces unchopped chocolate until it melts and the mixture is almost cool to the touch. To judge the warmth, insert a thermometer in the deepest part of the bowl. Wait 30 seconds, then check for 89 or lower degrees F. (Alternatively, touch the chocolate stirring spoon to just above your upper lip; the melted mixture should feel almost cool.) Keep stirring to cool the mixture if necessary. If some chunks remain unmelted when the desired temperature is reached, just lift them out and them aside. If the added pieces have completely melted and the mixture is still too warm, stir in the remaining 2 ounces unchopped chocolate and continue cooling down the mixture by stirring.
When the chocolate is cooled enough, lift out any unmelted chunks with a fork and discard. Add the previously sifted very fine peppermint shards to the chocolate. Stir well. Reserve the remaining larger bits for garnishing the top.
Immediately pour the chocolate-peppermint mixture into the prepared tray. Using an off-set spatula or table knife, spread the chocolate out to the edges; be sure the layer is evenly thick. Sprinkle the reserved peppermint bits evenly over the chocolate. Shake the tray back and forth and rap it on the counter several times to embed the candy bits in the chocolate. Immediately transfer the tray to the refrigerator, resting it flat. Refrigerate for 15 to 20 minutes or until the chocolate is completely set.
Store airtight at cool room temperature for up to 2 months. Makes about 1 1/3 pounds peppermint bark.
Doubling the Recipe: Follow the basic directions, except ready two 10-by 15- or similar rimmed trays or baking sheets. Break up or chop 2 pounds chocolate into small chunks; have 8 ounces unchopped chocolate on hand. In a large microwave-safe bowl, microwave the chopped chocolate and 2 tablespoons corn oil on 100-percent power for 2 minutes. Stop and stir. Continue microwaving on 50 percent power, stopping and stirring every 30 seconds until most of the chocolate is melted. Continue stirring until the chocolate completely melts. Stir in 4 drops peppermint oil ( if using) and 5 ounces of unchopped chocolate. Proceed as for the original recipe, except if the mixture is still too warm, stir in 3 more ounces unchopped chocolate. Continue exactly as for the original recipe, except divide the recipe evenly between the two pans. Makes about 2 3/4 pounds peppermint bark.