Vegan Macaroni and Cheese

Heat the oven to 400°F and arrange a rack in the middle.

Place 2 tablespoons of the oil in a large frying pan over medium-low heat until shimmering.

Add the onions and cook, stirring rarely, until deep golden brown and caramelized, about 1 hour. Season well with salt and pepper, remove to a medium bowl, and set aside.Meanwhile, place the broccoli, cauliflower, and garlic on a rimmed baking sheet.

Drizzle with 1 tablespoon of the oil, season with 1 teaspoon of the salt and 1/2 teaspoon of the black pepper, and toss to combine. Roast in the oven until the vegetables are browned in spots and cooked through, about 15 minutes.

Remove the baking sheet to a wire rack and set aside.Bring a large heavy-bottomed pot or Dutch oven of heavily salted water to a boil over high heat.

Add the pasta and cook according to the package directions or until just al dente.

Drain in a colander and rinse with cold water until cooled and the pieces are no longer sticking to each other (make sure to stir the pasta while rinsing); set aside in the colander. Reserve the pot (no need to rinse).While the pasta is cooking, place the coconut milk and walnuts in a blender and blend until smooth; set aside.Wipe out any water in the reserved pot, add the remaining 1/4 cup of oil, and place over medium heat until shimmering.

Add the flour, Dijon, paprika, cayenne, remaining 1 tablespoon of salt, and remaining 1/2 teaspoon of black pepper and whisk until smooth. Cook, whisking occasionally, until the flour has darkened slightly in color, about 2 to 3 minutes.

Whisk in the nutritional yeast and cook, whisking occasionally, until lightly browned, about 2 minutes.While whisking constantly, slowly add the reserved coconut mixture, then the soy milk, until evenly combined and smooth. (It will get very thick when you first add the coconut mixture, then thin out when you add the soy milk.) Increase the heat to medium high and cook, stirring occasionally, until the mixture comes to a simmer and thickens, about 5 minutes.Stir in the reserved pasta, caramelized onions, and roasted vegetables and cook, stirring occasionally, until the pasta and vegetables are heated through and steaming, about 3 minutes. Taste and season with salt and black pepper as needed.