Get the pork picnic roast out of the package, dry it off, and cross-hatch the skin to allow marinade absorption.
Mix the chopped rosemary, dried oregano, red pepper flakes, minced garlic, kosher salt, and olive oil.
Cover the cross-hatched pork roast thoroughly with the marinade, getting it into the grooves.
Place the roast in the refrigerator uncovered for about 4 days to let the flavors penetrate and moisture to escape the skin.
Fire up the smoker and preheat it to 300°F.
Cook the roast at 300°F for approximately 9 to 11 hours, until it reaches an internal temperature of 190°F to 195°F.