Cook broccolini in lightly salted simmering water for 2 to 3 minutes or until crisp-tender. Drain well. Transfer to a cutting board; coarsely chop and set aside.

For Pesto, place ⅓ cup pistachios and garlic clove in a food processor. Cover and pulse until coarsely chopped. Add cooked broccolini and ¾ cup parsley. Cover and process just until combined. With processor running, slowly add olive oil and process until smooth. Stir in Asiago cheese, crushed red pepper, ¼ teaspoon salt, and ¼ teaspoon black pepper. Set aside.

Preheat oven to 350°. Line a large rimmed baking pan with foil. Place a wire rack in the pan and lightly spray with nonstick spray. Set aside.

To roll-cut, the pork loin, place pork loin lengthwise on a cutting board. Make a ½-inch deep lengthwise slit on one side of the roast, 1-inch parallel from the cutting board. Continue cutting, gently unrolling the roast at the same time. When completed, the roast should be rectangular and 1-inch thick. If thickness is uneven, place a large piece of plastic wrap on top of roast; lightly pound to an even thickness using the flat side of a meat mallet.

Sprinkle both sides of pork with remaining 2 teaspoons salt, 2 teaspoons black pepper, and sugar. Place pork, cut side up, on cutting board. Spread with pesto to within ½-inch of all edges. Starting from a long side, tightly roll up into a spiral. Tie pork together at 1-inch intervals using 5 (10-inch each) pieces of kitchen string.

Heat vegetable oil in a large skillet over high heat. Carefully sear pork loin 1 minute on each side or until lightly browned. Place rolled pork, seam side down, on prepared rack in pan.

Roast pork for 55 to 70 minutes or until an instant-read thermometer inserted into center reaches 165°. Transfer pork to a clean cutting board. Loosely cover with foil; let rest for 15 to 20 minutes before slicing.

To serve, remove kitchen string. Slice pork and arrange on serving platter. Garnish with additional pistachios, additional parsley, lemon zest, and bay leaves, if desired.