1 lb (about 450 grams) sunchokes, peeled and roughly chopped
2 cups whole milk, plus more, as needed
3 cloves garlic, peeled
6 sprigs thyme
3 tablespoons butter
100 grams toasted walnuts
Salt, to taste
12 ounces (about 340 grams) bucatini
Fresh rosemary, finely chopped, for garnish
Parmigiano Reggiano, grated, for garnish
Lemon zest, grated, for garnish
Instructions
Prepare the purée: In a small-medium sauce pan, add sunchokes, milk, garlic, and thyme. Bring to a gentle simmer, cover (with a lid or parchment paper), and cook for about 15 minutes, or until sunchokes are very tender. Remove thyme sprigs, then add butter, toasted walnuts, and a large pinch of salt and use an immersion blender to mix the puree until velvety but still quite thick. If more liquid is needed, add a little extra milk. Taste, adjust salt levels to your preference, cover, and set aside.
Meanwhile, add bucatini to a large pot of boiling salted water. Cook for about 8 minutes, or until al dente. Reserve 1/4 cup of pasta water. To a large pan over high heat, add al dente pasta and pasta water with 1 1/2-2 cups of sunchoke purée (or enough to thoroughly coat the pasta). Transfer to serving plates and garnish with rosemary, Parmigiano Reggiano, and lemon zest.