First, cut the speck into strips about ⅓ inch wide; chop the strips crosswise to form little square bits of meat.
Pour the olive oil into a small skillet, and set it over medium heat. Stir in the onion, and cook until it starts sizzling. Spoon a tablespoon or two of water into the pan (so the onions soften without coloring), and cook for 3 or 4 minutes more. Scatter in the minced speck and cook for 2 or 3 minutes, until it has rendered its fat. Scrape the onion and speck into a large bowl and let cool.
Put the bread cubes in another bowl, and pour in the milk. Toss the cubes so they're all drenched, then let them soak up the milk for about 10 minutes, until completely saturated. By handfuls, squeeze the bread, discarding the excess milk.
Put the bread cubes in another bowl, and pour in the milk. Toss the cubes so they're all drenched, then let them soak up the milk for about 10 minutes, until completely saturated. By handfuls, squeeze the bread, discarding the excess milk.
Loosen the compressed bread, tearing it into shreds, and toss them into the bowl with the onions and speck. Add the grated cheese, herbs, 1⁄2 teaspoon salt, and pepper, and toss everything together. Pour the beaten eggs over the bread mixture, and stir to blend. Finally, sprinkle in ¼ cup of the flour and incorporate it to form a moist, sticky dough. Pick up a bit and form it into a ball: if it is too soft to keep a shape, stir in more flour, a tablespoon at a time.
Fill a wide pot with about 6 quarts water, and add the 1 tablespoon salt; bring to a boil. Put the white wine in a big skillet and allow it to simmer, uncovered, until reduced to ⅔ cup. Add the cold butter to the pan and continue to shake the pan until the butter has fully melted and emulsified with the wine reduction. Season with salt and pepper and set aside but keep warm.
Spread ½ cup flour on a tray or baking sheet. With floured hands, scoop up a small portion of dough, about 2 tablespoons. Shape the dough into an oval, tossing it from hand to hand, shaping it gently. Lay it in the flour, and roll the oval to coat it all over.
Set in on one side of the tray, and form dumplings from the rest of the dough in the same way. With the poaching water at a steady boil, drop in the dumplings, one at a time but quickly. Handle them gently so they don’t break apart in the water. With the end of a wooden spoon, gently check the bottom of the pot to ensure they are not sticking. Bring the water back to a steady simmer, but do not boil, as this could also break apart the canederli. Let them cook, uncovered, until they have risen to the surface of the water. Simmer them for another minute to ensure they are fully cooked, and test one dumpling before finishing the dish. They should no longer be wet in the center.
To finish, lift the dumplings with a slotted spoon, let drain over the pot for a few seconds, and gently place them in the warm wine and butter sauce. Spoon the sauce over the canederli and check the seasoning. Toss the dumplings gently in the pan. Serve them right away on individual plates or a platter, topped with grated Parmigiano-Reggiano or Grana Padano, fresh herbs, and more pepper.
If you are serving them as an accompaniment to braised or roasted meats, you can nap the pan juices over the canederli. You can also arrange the buttered canederli around the meat on a platter, letting them slowly absorb the juices or sauce.