In a medium bowl, whisk together brown sugar, reduced sodium soy sauce, sesame oil, crushed red-pepper flakes, and ground ginger until well combined. Heat 1 tablespoon of vegetable oil in a large cast iron skillet over medium-high heat. Add minced garlic, sautéing until fragrant, around 1 minute. Add ground beef, cooking until browned (3-5 minutes), crumbling as it cooks. Drain excess fat, then stir in the soy mixture, simmering for an additional 2 minutes.

In the same skillet, add another tablespoon of sesame oil over medium heat. Once hot, toss in the chopped kimchi along with a sprinkle of sugar for sweetness. Stir constantly for 3-5 minutes, until the kimchi caramelizes.

In a small bowl, mix together mayonnaise, Sriracha, and fresh lime juice. Whisk until smooth and creamy.

Warm mini flour tortillas in a dry skillet over low heat for 1-2 minutes on each side. Layer the beef mixture, caramelized kimchi, diced red onions, fresh cilantro, and drizzle with Sriracha mayo before serving.