This recipe celebrates whole-wheat pasta, leaning into its nuttiness without forcing it to be something it's not. You start off frying hazelnuts in olive oil (no pre-roasting necessary) until they’re deeply golden and irresistibly fragrant. When you remove the nuts from the skillet, you’re left with oil that’s infused with their richness—and ready to become pasta sauce. With chile flakes, garlic, and lemon—along with pecorino for more nutty saltiness and a pat of butter for gloss—it’s the ideal counterpart to the whole-wheat noodles: The crunchy hazelnuts provide a foundation of flavor that keeps the pasta from feeling out of place; the spicy, lemony sauce brightens it up to prevent the dish from feeling like it’s been buried underground. —Sarah Jampel
Bring a large pot of salted water to a boil. Add the pasta and cook until quite al dente, about 2 minutes short of the recommended time on the package.
Meanwhile, heat 3 tablespoons of oil in a large skillet over medium-high. When the oil is hot, add the sprig of thyme and let it sizzle. When it's changed color and shriveled, 1 to 2 minutes, add the hazelnuts. Cook, stirring often, until golden brown, 2 to 3 minutes, then use a slotted spoon to transfer nuts and thyme to a paper towel-lined plate. Sprinkle with salt.
Return the skillet to medium-high heat. Add the red pepper flakes and black pepper and let cook until fragrant, about 1 minute. Turn the heat down to low.
By now, the pasta should be finished. Scoop out 1 cup of pasta water to keep for the sauce, then drain the pasta and transfer to the skillet. Add the garlic and stir to combine. Mix in a couple tablespoons of pasta water, then sprinkle over a few tablespoons of pecorino and mix vigorously with a wooden spoon to melt in the cheese. Continue adding pasta water and cheese and mixing with verve until smooth and combined.
Add the butter and mix until you have a glossy sauce, then mix in the zest and juice from half a lemon. Mix in the reserved hazelnuts and thyme. Taste for salt and lemon.
Top with additional fresh thyme, black pepper, and grated pecorino.