In a food processor, combine fresh cilantro, roasted shelled pistachios, jalapeño, garlic, lime juice, and avocado or olive oil. Blend until silky and smooth, adding water to achieve desired consistency.

Heat a skillet over medium-high heat and drizzle with olive oil. Season shrimp with garlic powder, salt, and pepper. Cook for 2-3 minutes per side until pink and opaque, then remove from skillet.

In a large pot, bring salted water to a boil and add spaghetti. Cook according to package instructions until al dente, then drain and return to pot.

With pasta still warm, pour cilantro pistachio pesto over and toss to coat evenly. Add cooked shrimp and mix until combined. Adjust seasoning as necessary.

Serve portions onto plates, garnished with crumbled goat cheese, extra cilantro, and roasted pistachios.