In a pan over medium heat, toast fennel seeds and red pepper flakes about 1 minute, shaking often. Mix with sage, rosemary, garlic and orange zest. Lay belly skin side down on a cutting board. Score flesh side of belly in a cross hatch pattern, approximately 1 inch apart and with scores 1/3” to 1/2” deep Turn belly skin side up. With a paring knife, prick the skin of the belly all over 30-40 times. Using the spiked side of a mallet tenderizer, pound the skin side of the belly for2-3 minutes. Season flesh side of belly and entire loin piece liberally with seasoning mixture. Place loin in the center of the flesh side up belly and roll the belly around the loin. Secure roast by tying with kitchen twine every 1 inch down the roast, trimming excess twine after tying knots. Place roast on pan in the refrigerator uncovered overnight to dry skin. Remove roast from refrigerator two hours prior to cooking to warm to room temperature. Preheat oven to 400°F. Season outside of roast with salt, then roast in oven for 1 hour. Reduce temperature to 300°F and continue roasting about 1 ½ more hours. Remove when skin is crisp, deep golden brown and internal temperature reaches 140°F. Let rest 20-30 minutes before cutting (use a serrated blade to carve) into ½” to 1” thick slices.