1. Cook potatoes in a pot of boiling salted water for 15 minutes; drain well.
2. In a food processor, blend basil, pine nuts, garlic, salt, and pepper for about 30 seconds. Add the oil gradually and process until smooth.
3. Remove mixture from food processor and place in a mixing bowl; stir in cheese.
4. Spoon pesto sauce over warm potatoes; mix well. Garnish with fresh basil and serve immediately.