Add the cranberries and sugar to a medium saucepan set over medium heat and cook until the cranberries break down and the mixture reduces by two-thirds, 12 to 15 minutes. Stir in the mustard and remove from the heat. Using an immersion blender or blender, pulse until the mixture achieves a smooth consistency. Season with salt if needed.
Combine the breadcrumbs, cheese and cornmeal in a shallow dish. Sprinkle each cutlet with salt and pepper on both sides. Coat each cutlet with sour cream and press into the breadcrumb mixture. Place on a baking sheet fitted with a wire rack.
Heat the coconut oil in a cast-iron skillet set over medium heat. In batches, pan-fry the turkey cutlets until the first side is golden brown, about 3 to 4 minutes. Flip and cook until cooked through and golden brown, another 3 minutes. Add more oil as needed and repeat for the remaining batches. Serve with the cranberry mustard dipping sauce.
The cranberry mustard dipping sauce makes about 1 1/2 cups and can be stored in the refrigerator for up to 7 days. Serve warm or at room temperature.
When blending hot liquid, first let it cool for five minutes or so, then transfer it to a blender, filling only halfway. Put the lid on, leaving one corner open. Cover the lid with a kitchen towel to catch splatters, and pulse until smooth.