Preparation:

Step 1: Prepare the Chicken

Start by slicing the boneless, skinless chicken breast into thin slices. This helps the chicken cook quickly and evenly. You can also partially freeze the chicken to make it easier to slice. Next, place the sliced chicken in a resealable plastic bag and add 1/4 cup of cornstarch. Seal the bag and shake it well to coat the chicken evenly with the cornstarch.

Step 2: Cook the Chicken

Heat the vegetable oil in a large pan over high heat. Once the oil is hot, add the chicken slices to the pan in a single layer. Season the chicken with salt and pepper (be mindful that the sauce will add some saltiness). Cook the chicken for about 3-4 minutes per side or until it becomes golden brown and crispy. Depending on the size of your pan, you may need to cook the chicken in multiple batches to avoid overcrowding.

Step 3: Prepare the Sauce

Remove the chicken from the pan and place it on a plate lined with paper towels to drain any excess oil. In the same pan, add the minced garlic and ginger, cooking them for about 30 seconds until fragrant. Add the soy sauce, sesame oil, water, and dark brown sugar to the pan. Stir the mixture and bring it to a simmer.

Step 4: Thicken the Sauce

In a small bowl, mix the remaining 2 teaspoons of cornstarch with 1 tablespoon of cold water to create a slurry. Add this slurry to the simmering sauce and bring it to a boil. Let it boil for 30-60 seconds until the sauce thickens to your desired consistency.

Step 5: Combine the Chicken and Sauce

Return the crispy chicken to the pan and toss it in the thickened sauce until all the pieces are well-coated. Add the green onions and give everything a final toss. Serve the Mongolian chicken stir-fry hot, either over steamed rice, zucchini noodles, or cauliflower rice.