Preheat the oven to 400ºF. Place the sweet potatoes on a baking sheet lined with a silicone mat or parchment paper. Prick each potato with a fork in two or three places and bake until tender, about 1 hour.
When the potatoes are done baking, transfer them to a work surface and allow to cool slightly. Cut each sweet potato in half lengthwise and scoop out the insides of the potatoes into a bowl, leaving about ¼ inch of potato attached to the skin. Add the peas and chives and mix well. Spoon the mixture into each half and return the stuffed sweet potatoes to the oven for about 15 minutes to heat through. Sprinkle with almonds, drizzle with Balsamic-Date Glaze, add a few grinds of black pepper to taste, and serve hot.
Balsamic Date Glaze
Soften the 1/2 cup of dates by soaking in warm water for about 10 minutes. In a blender, combine the dates and their soaking water with the balsamic vinegar. Blend until smooth.
Final step of the Balsamic Date Glaze
Transfer the mixture to a small saucepan and bring to a boil; then reduce the heat to low. Simmer on low until the glaze is reduced and thickened, stirring frequently.