Preheat grill or barbecue.
Place octopus in cold water with a cork and bring to a boil. Lower heat to low boil and cook 35 to 40 minutes until tender. Remove, rinse and cut into 4 pieces.
In a mixing bowl, stir together olive oil, lemon zest and juice, red pepper, oregano and black pepper. Marinate octopus pieces for 10 minutes and place on a grill. Cook until crispy and slightly charred, about 5 minutes per side.
When octopus goes on grill, clean escarole of flimsy outer leaves. Cut in half lengthwise and rinse well to remove grit. Place cut side down on grill and cook until lightly charred, about 3 to 4 minutes on one side. Turn and cook 2 more minutes and remove.
Remove octopus and replace in marinade, cut into bite-sized pieces with scissors and pour over escarole, sprinkle with fresh mint and serve.