Prepare all ingredients as listed.
Spread the mayonnaise evenly onto the baguette.
Layer with arugula, tomato drizzled with olive oil and seasoned with black pepper, and dried oregano, turkey, red onion, pepperoncini, and avocado. Cut in half if preferred.
In a glass, combine sparkling water, lemon slices, and chia seeds. Stir well and allow the chia seeds to hydrate briefly, then stir again to prevent clumping.
Serve the sandwich with carrots, hummus, and lemon chia sparkling water.