Prepare all ingredients as instructed above.
In a bowl, season the shrimp with Cajun seasoning and toss with extra-virgin olive oil until evenly coated.
Preheat a grill or grill pan to medium heat.
In a small bowl, whisk together the mayonnaise, sriracha sauce, Creole mustard, horseradish, Worcestershire sauce, minced shallot, minced garlic, and lemon juice to make the remoulade.
Grill the shrimp for about 2–3 minutes per side, or until they are opaque and cooked through. Cook shrimp to an internal temperature of 120°F (48°C).
Lightly toast the baguette halves on the grill until golden and crisp.
Assemble each po' boy by layering the inside of the baguette with shredded romaine lettuce, tomato slices, jalapeño slices (if using), and grilled shrimp. Drizzle generously with remoulade sauce.
To make the sparkling chia fresca, combine all the ingredients together. Stir well and let sit for 5 minutes to allow the chia seeds to bloom.
Serve the grilled shrimp po’ boys with carrot sticks and hummus, alongside sparkling chia fresca. Enjoy!