For the pickled red onions: Pour simmering hot water over the onions and beet and let stand for 10 minutes. Drain and repeat two more times. Heat 8 cups water with the salt, sugar, pickling spice and some black pepper until the salt and sugar are completely dissolved. Pour the hot brine over the onions, cover and refrigerate for 24 hours.
For the tomato preserves: Combine the tomatoes, oil, garlic, sugar and paprika in a non-reactive saucepot. Simmer over low heat until the tomatoes are tender. Crush the tomatoes with a wooden spoon and cover with additional olive oil if necessary. Fold in the basil, season with salt and pepper and chill.
For assembly: Toast the baguettes on a panini press until warm and crispy. Spread 1/2 ounce mayonnaise and 1/2 ounce tomato preserves on each. Layer on 2 slices each of the soppressata, capocollo and coppa. Top with 1 slice of cheese per baguette. Finish with 1 ounce of the giardinara, 1 ounce of the pickled red onions and 1 ounce of the lettuce. Close and cut in half. Serve immediately. Reserve remaining pickled red onions for another use.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.