In an electric food processor or blender, blend cilantro, garlic, vinegar, Parmesan cheese, cayenne pepper, nuts, and salt. Add ¼ cup of the olive oil, and blend the pesto. Add more olive oil until the pesto reaches your desired consistency.
Pour pesto in a small saucepan and warm over low heat, stirring constantly, until pesto begins to simmer. Pour over cooked pasta or potatoes and toss.