Prepare all ingredients as described above.
In a bowl, season the shrimp with Cajun seasoning and toss with extra-virgin olive oil until evenly coated.
Bring water to a simmer in a small pot. Remove from heat and steep ginger tea bags in the hot water for 10 minutes. Sweeten with sugar or honey to taste. Remove the tea bags, let cool, then refrigerate until ready to serve over ice.
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 fresh 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 125°F (51°C).
Lightly toast the baguette halves on the grill until golden and crisp.
Assemble each po' boy by layering shredded romaine lettuce, tomato slices, jalapeño slices (if using), and grilled shrimp inside the baguette. Drizzle generously with remoulade sauce.
Serve the grilled shrimp po' boys with fresh cherries and ginger iced tea. Enjoy!