To prepare dried chickpeas: combine chickpeas with 2 cups of water and place in a bowl. Allow to soak overnight at room temperature. Drain, rinse well, then transfer to pot with 3 cups of water and bring to boil for 5 minutes. Reduce to a simmer, then cook for an additional 45 minutes. Drain.
Cook pasta until al dente, reserving 1 cup of pasta water. Drain, rinse, and place back in pot.
In a food processor, combine cooked chickpeas and remaining ingredients, except parsley, and process until smooth. Add in as much of the oil from the sun-dried tomatoes until the mixture is smooth and creamy (but still thick).
Add pesto in with pasta, along with enough reserved pasta water until the sauce is the consistency you want. Season to taste with salt and pepper, and garnish with parsley.
Notes
You can use 1 cup of canned chickpeas (rinsed) for a quicker version, but you won’t get the smooth and creamy texture as you will by using the dried ones.