Prep your vegetables:

1. Peel the carrots and the daikon and then trim the ends. You can use either a knife or a mandoline to julienne the vegetables to create thin matchsticks. If using a knife, slice the vegetables thin on the diagonal, then stack the slices and cut through them again to create thin strips. Set aside in two separate containers.
2. Salt the carrots and daikon with ½ teaspoon of salt each, mix well with your hands, and let sit for 10 mins. Then lightly squeeze out the accumulated juice, and put each vegetable back into the individual containers. This keeps the carrot color from bleeding into the radish.
3. In a microwave proof bowl, stir together the sugar and water. Then microwave for about 1 minute to help the sugar dissolve. Stir in the vinegar then pour the vinegar marinade over the vegetables equally and let them soak for at least 30 mins or overnight. The pickles will keep in the refrigerator for 1 week. Drain the pickles before using.
4. In a small bowl, stir together the mayonnaise, sriracha, honey, garlic powder, and lime juice. Set aside until ready to use. This sauce also keeps for a week.
5. Cut the cucumber into a julienne by slicing the vegetables thin on the diagonal, then stacking the slices and cutting through them again to create thin strips. Set aside or refrigerate until ready to use. 

Make the meatballs:

1. In a large bowl, combine the beef, lemongrass, garlic, scallion, fish sauce, soy sauce, hoisin, five spice powder, cornstarch, and black pepper. Mix gently until everything is combined.
2. Scoop the beef into 2 tablespoon balls with a spoon or an ice cream scoop. You should yield around 16 meatballs. Wet your hands with a little water if the mixture is sticky and pat the meat so it is a flat oblong shape which will fit the bread better.
3. Heat a large pan over medium high heat and cook each meatball for 2-3 mins per side until just cooked through. Adjust the heat a little if the patties are starting to brown too much. (I turn off the heat and cover the pan with a lid for the last minute.)

Assemble the sandwiches:

1. To assemble sandwiches, slice the baguettes in half horizontally. Spread a generous amount of the sauce onto each half of the bread. Place four meatballs per baguette. Top with some of drained carrot and radish pickles, sliced cucumber, jalapeño, and cilantro. Top with the other half of the bread. (Cut the bread into 4 lengths first if using a full size baguette). Serve immediately.