If you don't have a food processor, you can hand chop the herbs and combine it by hand. You could also use an herb cutter and that'll work great too. Start by chopping the herbs and placing them in a container. I find a mason jar works perfectly. Add to it all the remaining ingredients and shake well. It tastes delicious right away, but gets better as it hangs out together in the fridge.
If using a food processor, place the parsley and cilantro in the food processor and gently pulse. You don't want to purify this, just chop it up slightly. Add the remaining ingredients and pulse until just blended. Store in a jar or other container.