Spread crushed walnuts on a baking sheet and bake in an oven heated to 350 degrees for 8 to 10 minutes, or until slightly brown.
In a food processor or blender, combine walnuts, garlic, cilantro leaves, sun-dried tomatoes, olive oil, vinegar, Parmesan cheese, and chili pepper. Puree until smooth, adding more olive oil if needed until the pesto reaches desired consistency. Season with salt.
Put pesto into a small container; cover tightly. It can be stored in the refrigerator for up to 3 days.