Peel and mince ginger and garlic. Trim, then thinly slice the scallions - keep the whites and greens separate (you will cook with the whites and use the greens for a garnish).

Drizzle 1 tbsp of olive oil into a pan preheated over medium-high heat. Use paper towels to pat the chicken dry and then add them in a single layer to the oiled pan. Cook 2-4 minutes per side (until lightly browned but not cooked completely through). Remove from the pan and set aside.

Whisk together the soy sauce, sugar, rice vinegar, and cornstarch in a small bowl. Drizzle the pan with the remaining 1 tbsp of olive oil. Add the scallion whites, garlic, and ginger to the pan and toss to cook for 1-2 minutes (until softened). Stir in soy sauce mixture and simmer until slightly thickened (about 2 minutes).

Return the chicken to the pan and toss to coat with the thickened soy sauce. Allow to completely cook through, about 2-3 minutes. Add to microwaved fried rice and garnish with scallion greens and sesame seeds.