- To prepare chile sauce, combine chiles, garlic, onions, vinegar, and sugar in a saucepan over medium heat. Bring to a simmer until ingredients are soft and translucent (they should look almost candied), about 20 minutes. Remove sauce from heat, and let cool completely then puree in a blender.
- In a non-reactive dish, season pork with salt and pepper and then cover with chile sauce, reserving 1/3 cup. Cover and marinate for at least 8 hours, or overnight.
- The next day, prepare your fire. When the flames no longer lap at the grates, push coals to one side. Fill and aluminum roasting pan with beer, and place in vacant spot where the coals were.
- Place pork onto grates over roasting pan, and roast meat, turning occasionally until internal temperature reaches 200 degrees, about 4 hours. Remove from grill.
- Places ears of corn and onions directly onto coals, turning to char evenly, until exteriors are completely blackened. Remove from coals and cool. Shuck corn and remove outer layer of onion. Discard husks and onion skins by tossing into fire.
- Cut corn into 2-inch pieces and pull onion apart into leaves. In a large bowl, toss corn and onions with lettuce. Add pork, lemon juice, and reserved 1/3 cup chile sauce. Toss well.
- Transfer onto large platter. Garnish with edible flowers from the garden or the wild, like nasturtium flowers, bee balm, honeysuckle flowers, and borage. Set pork drippings in a bowl and let guests dip bread into drippings.