Place the orange juice in a small skillet and simmer over medium-high heat until thick and syrupy and reduced to about 1 tablespoon. Cool to room temperature. Place in a small bowl and mix in the butter and orange zest until well-combined. Place the bowl in the fridge until ready to top the fish. Preheat the oven to 375 degrees F. Lay the sole fillets in a single layer on a baking sheet lined with parchment paper; season with salt and pepper. Top each fillet with an equally sized spoonful of the orange butter. Bake for 8 to 10 minutes, or until just cooked through. Carefully lift the sole off the baking sheet and onto dinner plates. Spoon the buttery juices from the baking sheet over the fish, sprinkle with the almonds and parsley before serving.
Note: To toast almonds, place a single layer in a small baking pan. Bake in a 300 degrees F oven for 10-15 minutes, or until lightly toasted.