Process parsley, lemon juice, Dijon, garlic, 1 1/2 teaspoons of the salt, and 1 teaspoon of the pepper in a food processor until well combined, about 1 minute. While food processor is running, slowly add 2/3 cup of the extra-virgin olive oil. Transfer lemony-herb dressing to a jar with lid; set aside. (The dressing can be made ahead and stored in refrigerator up to a week.)