Boil a large pot of water over high heat. Once it reaches a rolling boil, add the fresh ramen or udon noodles, cooking them according to package instructions until just tender, about 3-5 minutes. Drain and rinse under cold water to stop the cooking process.

In a small mixing bowl, combine gochujang, soy sauce, brown sugar, sesame oil, and minced garlic. Whisk until smooth. If too thick, add a tablespoon of water.

Heat 2 tablespoons of oil in a large skillet over medium-high heat. Add the chicken thighs, cooking for 6-8 minutes until golden brown and fully cooked.

Reduce heat to medium, pour the gochujang sauce over the chicken, and stir to coat. Cook for an additional 2-3 minutes until the sauce becomes glossy.

Add the cooked noodles directly into the skillet with chicken and sauce. Toss everything together gently and heat for another 1-2 minutes.

Remove from heat, transfer to serving bowls, and garnish with scallions and sesame seeds. Serve immediately.