Whole-grain spaghetti gets its striking color from a quick toss with pureed beets (a prime source of the phytonutrient betalain). Sun-dried tomatoes -- richer in lycopene than fresh ones -- lend the sauce a caramelized sweetness.
red beets, trimmed, scrubbed
olive oil, plus more for drizzling
Preheat oven to 425 degrees. Drizzle beets with oil and season with salt. Wrap tightly in foil and roast until tender, 1 hour. Peel and chop once cool.
Pulse beets, walnuts, and tomatoes in a food processor. Season with salt and red-pepper flakes.
Cook pasta in salted water according to package directions. Drain, reserving 1 cup water, and return to pot.
Toss with beet mixture, adding pasta water until creamy. Serve with ricotta, a drizzle of oil, and red-pepper flakes.