Slice the loaf of bread in half horizontally and remove some of the soft interior to make a shallow boat of both the top and bottom halves.
To make the burrata and curried cauliflower sandwich: On a rimmed baking sheet, combine the cauliflower, olive oil, curry powder and salt; toss well to coat. Roast until tender and beginning to brown, 20 minutes. Cool completely before using.
Meanwhile in a small bowl, mix together the mayonnaise and basil with a rubber spatula. Refrigerate until ready to use.
On one-third of the loaf of bread, spread the cut-sides (top and bottom) with the basil mayonnaise. Tear half of the burrata over the mayonnaise on the bottom half. Season with a pinch of salt and then pile the roasted cauliflower on top of the burrata. Tear the remaining burrata over the cauliflower. Top with the arugula.
For the Italian sandwich: On the next third of the bread, shingle four pieces of provolone on the bottom half and four on the top. Layer the coppa, finocchiona and mortadella on top of the bottom half. Follow with the sliced tomato, a pinch of salt, the shredded lettuce and the giardiniera. Drizzle the greens with the white balsamic.
For the turkey and cheese sandwich: On the last third of the bread, spread the insides (top and bottom) with the mustard and then the sweet relish. Shingle the turkey over the bottom and place the Cheddar on top.
Place the top half of the bread of the bottom and tightly wrap with plastic wrap. Refrigerate for at least 4 hours. Cut into slices and secure with toothpicks if needed.