Step 1

In a small bowl, stir together the panko and milk; set aside while you cook the pasta. In a large pot, bring 4 quarts water to a boil. Stir in the pasta and 1 tablespoon salt, then cook, stirring occasionally, until 2 to 3 minutes shy of al dente. Add the chard to the pot and cook until the pasta is al dente. Reserve about 1½ cups of the cooking water, then drain the pasta and greens; return them to the pot.

Step 2

Meanwhile, in a food processor, combine the panko mixture, walnuts, Parmesan, oil, garlic, lemon juice, marjoram, and ¼ teaspoon each salt and pepper.Pulse until the walnuts are roughly chopped, about 3 pulses, then process until the mixture resembles fine breadcrumbs, about 20 seconds. Add 1 cup of the reserved pasta water, then process until smooth and creamy, about another 30 seconds, scraping down the bowl once.

Step 3

Add the walnut sauce to the pasta-chard mixture, then toss to combine, adding reserved pasta water as needed so the sauce coats the noodles. Serve drizzled with additional oil and sprinkled with grated Parmesan.