While the pasta cooks, make the pesto.
Start by placing the cashews or almonds--use whatever you have on hand, sea salt, ground black pepper, cilantro, garlic, and nutritional yeast (if using) in the food processor. Pulse a few times to bring everything together, then process until eveyrthing is pretty finely ground.
Now add the adobo sauce, 1 chipotle pepper, the olive oil, and the water. Process until the oil and water incorporate and the pepper breaks down. Taste. It should be a little salty! Remember, you are putting this sauce over a pound of pasta, so the salt level will dilute once the pesto is coating the pasta.
If you would like to add more smoky flavor and heat, add another chipotle pepper. Keep adding one pepper at a time, processing, and tasting until you get to your desired flavor/heat level. I usually find that 3 chipolte peppers is perfect, but each can of peppers is slightly different, so definitley go by taste!
Process until the pesto is mostly smooth. There will still be some texture. Add the lime juice, and process once more to incorporate. Pesto is done!