To a blender, add the basil, pistachios, parmesan, garlic clove, olive oil and 1/2 teaspoon salt. Pulse until very smooth, scraping down the sides as needed, for about 1 to 2 minutes. Give it a taste and adjust the salt to your liking. I added an extra pinch.
To a medium skillet, set over medium heat, add the olive oil. When the oil is hot, add the tomatoes and cook until seared and blistered, about 3 minutes. Shake the skillet around every so often.
Meanwhile, bring a pot of salted water to a boil. Boil the pasta according to the package’s instructions. Scoop out about a 1/2 cup of pasta water. We’ll use this in the sauce!
Drain the pasta and transfer it to the skillet with the blistered tomatoes. Add the reserved pesto and pour in a few splashes of pasta water. Give it a good mix until the pasta is fully coated with the pesto. Add more pasta water if you need it.
Divide the pasta amongst bowls/plates and garnish with parmesan and a bit of crushed pistachio.