1 head cauliflower, cored and cut into florets, plus a few smaller florets, reserved for garnish (optional)
1 cup vegetable stock (or, alternatively, chicken stock)
1 cup whole milk
Salt, to taste
12 ounces (about 340 grams) rigatoni
1 tablespoon butter
1/2 cup panko
1/2 cup pecorino, grated, for garnish
Chili flakes, for garnish
Instructions
In a saucepan over medium heat, add olive oil. Once hot, add leeks and garlic. Cook until fragrant, softened, and slightly translucent, stirring as you go. Add cauliflower florets, stir, and continue to cook for a few more minutes. Add stock, milk, and a large pinch of salt. Simmer until the cauliflower is very tender and the liquids have reduced, about 10-15 minutes. Use an immersion blender to make the purée smooth. Taste, add salt as needed, cover, and set aside.
To a large pot of boiling salted water, add rigatoni. Cook until al dente, about 10 minutes. Reserve 1/4 cup pasta water.
While you wait for the pasta to cook, add butter to a large pan over medium heat. Once the butter has melted, add panko and toast until evenly golden brown, stirring as needed. Remove from heat, transfer to a paper towel-lined plate, and set aside. If using small florets for garnish, add olive oil to the pan over high heat, add florets, season with salt, and sear. Transfer to a plate and set aside.
When the pasta is ready, be sure that the pan is over high heat. Transfer pasta water, pasta, and 1 1/2-2 cups of cauliflower purée (or enough to coat the pasta entirely). Stir vigorously with a spatula until the sauce is as thick as you like. Transfer to serving bowls and garnish with a generous amount of toasted panko, pecorino, and chili flakes. If using, garnish with seared cauliflower florets, too.