This chicken is bathed in a 4-ingredient, sweet/tangy/salty blend of pineapple juice, soy, brown sugar, and mirin. It's perfectly balanced, and simmers into scrumptious glaze.
In a small bowl, whisk together the pineapple juice, soy sauce, mirin, and brown sugar. Set aside.
Heat the oil in a large skillet over medium-high heat. Add the chicken and cook until browned on all sides. Season the chicken with salt and black pepper.
Add the pineapple juice mixture and bring to a simmer. Reduce the heat to low and simmer for 5 minutes, until the chicken is cooked through.
Meanwhile, cook the ramen noodles according to the package directions (without the seasoning packet). Drain, return the noodles to the pan and toss with the sesame oil.
Transfer the to individual plates and cover with foil to keep warm.
Dissolve the cornstarch in about 2 tablespoons of water and add the mixture to the chicken. Simmer for 1 to 2 minutes, until the sauce thickens. Spoon the chicken and sauce over the ramen noodles and top with green onions and cilantro.