For the Mexican Street Corn Salad: In a large skillet, heat the oil over high heat. Cook the corn until it begins to char. Remove the pan from the heat and allow the corn to cool completely before using in the salad.
Assemble the salad: In a bowl, combine the corn, radish, scallions, and lime juice, and season with salt and pepper. Toss the corn mixture with chipotle mayo until completely coated. Add a little more if desired. Sprinkle the salad with cilantro, cotija, and chili powder. Refrigerate until ready to serve.
For the Filling: Heat the oil in a large skillet over medium heat. Add onion and cook until soft, about 5 minutes, then add garlic and cook until fragrant, 1 minute more. Add ground beef and cook, breaking meat up with a wooden spoon, until no longer pink, 5 minutes. Drain the grease.
Return the pan to medium heat, and stir the tomato paste into the beef. Add oregano, cumin, and paprika, and season with salt and pepper. Add tomatoes and jalapeños and cook until warmed through, about 3 minutes. Remove from heat and let cool slightly.
Preheat oven to 400℉ (204℃) and line a baking sheet with parchment paper.
For the Empanadas: Lightly moisten the outer edge of a dough round with water, place about 2 TBSP of filling in the center, and top with cheese. Fold the dough in half over the filling. Use a fork to crimp the edges together. Repeat with the remaining filling and dough.
Place empanadas on a prepared baking sheet and brush with egg wash. Bake until golden and the filling is warmed through, about 25 minutes.
For the Mojito: In a glass, muddle the fresh mint leaves and sugar together until the mint is fragrant. Add fresh lime juice and stir well. Fill the glass with ice cubes. Pour in the white rum, if using. Top up with sparkling water. Stir gently to combine. Garnish with lime slices and mint sprigs.
Serve: Garnish the empanadas with cilantro and serve with sour cream, Mexican street corn salad, and mojitos.