Preheat a grill pan over medium-high heat. Rub the corn with 1 tablespoon canola oil and season with salt and pepper. Place the corn on the grill and cook until lightly charred in spots and the corn is warmed through, 10 to12 minutes. Remove from the heat and, when cool enough to handle, cut the kernels from the cob. Reserve 1 ear of corn for another use, such as Round 2 Recipe Silver Dollar Corn Fritters.
In a large bowl, whisk together the cider vinegar, garlic, cayenne pepper and remaining canola oil. Add the beans and onions, and toss to coat. Reserve 1 cup bean mixture for another use, such as Round 2 Recipe Silver Dollar Corn Fritters.
Stir the ham, parsley, green bell peppers and corn kernels into the bean mixture. Season with salt and pepper. Remove the outer leaves of the lettuce head. Serve the salad scooped into cups of lettuce leaves.