Peel sweet potatoes and discard skin. Using the vegetable peeler or a mandoline make long thin chips by peeling/slicing lengthwise from top to bottom. Place in a bowl of ice water and chill for 1 hour. Drain in a colander and layout on paper towels and pat dry.
Combine chili powder, garlic powder, a pinch of cayenne, cumin and salt and pepper.
Heat vegetable oil in a large pot to 375 degrees F. Fry the potatoes in single layer batches for 2 to 3 minutes until golden brown. Lift chips out with slotted spoon and drain on paper towels. Season with the spice mixture and serve immediately. Serve as an appetizer with Blue Cheese and Chives dip.
Blue Cheese and Chive Dip:
Combine sour cream, mayonnaise, lemon juice, blue cheese, honey and chives in a medium bowl. Season with salt and pepper and garnish with chives. Serve with spicy and sweet potato chips.