Macaroni and Cheese With Black Beans and Chipotle Recipe

Combine cornstarch, evaporated milk, and eggs in a medium bowl and whisk until homogenous. Set aside. Cook pasta in a large stock pot in salted water according to package directions. Drain, reserving 1 cup pasta cooking water. Return to stock pot and add cooking water, beans, chipotle chilies, serrano or jalapeño, evaporated milk mixture, and cheeses. Cook over low heat, stirring constantly, until cheese is melted and sauce is creamy and smooth. Stir in cilantro and scallions, reserving some for garnish. Transfer to serving bowl, top with remaining cilantro and scallions, and serve immediately.