Bring a large pot of water to a boil, over high heat.
In a small mixing bowl, combine the olive oil, basil and garlic. Heat in the microwave for 20 seconds. Remove and stir. Repeat for another 20 seconds. Set aside.
Rub half the lemon over the entire artichoke (inside and out). Place cut side down in the boiling water for 25 minutes to steam.
In a large bowl, combine the mayonnaise, ketchup, 1 tablespoon lemon juice, 1 tablespoon olive oil mixture and Sriracha Roster Sauce (optional) and stir to combine. Place in the microwave for 15 seconds and stir. Repeat for another 15 seconds. Set aside.
After steaming, rub 1 teaspoon of olive oil mixture over the entire artichoke. Season with lemon pepper.
Turn the grill on high heat. Place the artichokes, cut side down, on the grill for 10-12 minutes.
Remove and enjoy immediately!