Preheat the oven to 350°. In a medium nonreactive saucepan, bring the orange juice to a boil over high heat. Boil until reduced to 1/3 cup, about 30 minutes. Transfer the orange syrup to a medium bowl, add the cayenne and let cool.
Meanwhile, toast the almonds on a small baking sheet in the oven for about 5 minutes, or until golden. Let cool. Transfer to a mini-processor and pulse until finely ground, or mince with a knife. Add the almonds to the orange syrup along with the mint, maple syrup and lemon juice. Season with salt and pepper.
The chutney can be refrigerated overnight. Let return to room temperature before serving.