Preheat the oven to 400 degrees Fahrenheit.
Peel the sweet potatoes, and cut into slices approximately 2-3 inches long by 3/4 inch wide.
Place the potato slices in a large mixing bowl and coat with the olive oil.
Add the rosemary, thyme, oregano and peppercorns to a mortar and crush with the pestle.
Sprinkle the herbs and salt over the potatoes and mix until the potatoes are evenly coated.
Place the potatoes on a large baking sheet.
Place the sheet in the oven, and bake for approximately 30 to 40 minutes, stirring half way through.
Place the roasted sweet potatoes on a serving dish and serve family-style at your next Thanksgiving Day, Christmas Dinner or other holiday celebration