How to Make It
In a large bowl, whisk both flours with a generous pinch of salt and make a well in the center. Add the egg yolks, whole egg, olive oil and 1 tablespoon of water. Using a fork, gradually whisk the flours into the wet ingredients until a shaggy dough forms. Scrape the dough out onto a very lightly floured work surface and knead until stiff but smooth, about 5 minutes. Wrap in plastic and let rest at room temperature until soft and relaxed, 30 minutes to 1 hour.
Divide the dough into 4 pieces and work with 1 piece at a time; keep the rest covered. Press the dough to flatten. Using a pasta machine, starting at the widest setting, run the dough through successively narrower settings until you reach the second to thinnest; the dough should be a scant 1/8 inch thick. Cut the pasta sheet into 10-inch lengths, lay them on a lightly floured work surface and generously dust with 00 flour. Repeat with the remaining pieces of dough.
Working with 1 sheet at a time, loosely fold the pasta over itself 3 or 4 times like a ribbon. Using a very sharp knife, cut across the folds into 1/8-inch-wide noodles. Uncoil the tajarin and toss with flour. Transfer to a lightly floured baking sheet. Repeat with the remaining sheets of pasta.
Preheat the oven to 375°. Spread the pecans in a pie plate and toast for 7 minutes, until golden. Let cool, then coarsely chop.
Set up an ice bath. In a large saucepan of salted boiling water, blanch the kale until barely tender, about 2 minutes. Drain; transfer to the ice bath. Drain again and pat dry.
Light a grill and oil the grate. Spread the kale on the grate and grill over high heat, turning occasionally, until charred in spots, about 3 minutes. Let cool slightly, then coarsely chop. In a blender, combine the kale with the anchovies, lemon juice, garlic, half of the toasted pecans and the 1/4 cup of pecorino. With the machine on, gradually add the 1 1/2 cups of olive oil and puree until smooth. Season generously with salt and pepper.
In a large saucepan of salted boiling water, cook the pasta until al dente, about 1 minute. Drain, reserving 1 cup of the cooking water.
Wipe out the saucepan and add the pesto to it. Cook over moderate heat, stirring, until just hot, about 2 minutes. Add the pasta along with 1/2 cup of the reserved cooking water and toss until hot and evenly coated with pesto, about 2 minutes. Add a little more pasta water if necessary. Transfer the tajarin to shallow bowls. Top with shaved pecorino, chive flowers and the remaining chopped pecans. Serve right away.
00 flour is available at specialty food markets and from kingarthurflour.com.