Bring water to a boil, season with salt, add farfalle and cook following packet instructions, then reserve ½ cup pasta water and drain in a colander. The starchy water will help loosen the sauce later.
Melt butter in a skillet over medium heat, then add shallot, garlic, and dried thyme and cook 4 to 5 minutes until shallot softens and aroma builds.
Place ricotta and herbs in a blender, blend 10 to 20 seconds until the mixture feels whipped and light, which gives the sauce an airy texture.
Add drained pasta and whipped ricotta to the skillet, stir gently, then add reserved pasta water in small splashes until the sauce coats the pasta and warms through in a few minutes.
Divide pasta into bowls, sprinkle pistachio nuts and extra herbs, season with salt and pepper, and serve while hot to keep the sauce creamy.