Place 1 cup walnuts in a bowl, then add enough cold water to cover.
Let the walnuts soak for at least 6 hours in the fridge (or overnight).
Drain and discard the soaking liquid, then add the walnuts to a high-powered blender.
Add 1 cup cold water, 1 garlic clove, 1/3 cup nutritional yeast, 3/4 teaspoon salt, 1/4 teaspoon dried rosemary, 1/4 teaspoon dried sage, 1/4 teaspoon dried thyme, and 1/8 teaspoon black pepper to the blender.
Blend until smooth and creamy.
Heat to your desired temperature on the stovetop or in the microwave, then toss with cooked pasta (this recipe makes enough sauce for 4 servings of pasta). Or use anywhere else a savory, creamy sauce works well.