2. Combine the olive oil and onion in a large skillet and cook over medium-high heat until just golden, about 5 minutes. Add the anchovies and mash them into the onions, then stir in the pine nuts, currants, and the cauliflower. Stir the estratto into the wine until dissolved, then add to the cauliflower with I cup reserved cooking water and simmer until the cauliflower is falling apart (add a bit more cooking water if mixture gets too dry). Season with salt and pepper to taste and set aside.
Cook the perciatelli in a large pot of boiling well-salted water (for al dente it’s usually 7 minutes). Drain and gently toss with the cauliflower sauce and sprinkle the toasted breadcrumbs on top.