Step 1: Gather all your ingredients. Cut the boneless, skinless chicken thighs into uniform bite-sized pieces. Slice your mushrooms (button or cremini work great here). Mince your fresh garlic and ginger finely. Having everything prepped makes the stir-fry process smooth and quick!
Step 2: Heat 1 tablespoon of vegetable oil in a large skillet or wok over medium-high heat. Once hot, add your chicken pieces, seasoning them lightly with salt. Cook for 5-7 minutes, stirring occasionally, until the chicken is beautifully browned and cooked through. Remove the chicken from the skillet and set it aside on a plate.
Step 3: In the same skillet (no need to clean it!), add the minced garlic and ginger. Sauté for about 30 seconds until they become fragrant, being careful not to burn them. Next, add the sliced mushrooms to the skillet. Cook for another 3-4 minutes, stirring, until the mushrooms are tender and have developed a nice brown color.
Step 4: Return the cooked chicken to the skillet with the mushrooms. Pour in the chicken broth, soy sauce, and 1 tablespoon of black pepper (or more, to taste!). Stir everything together to combine. In a small bowl, whisk together 1 tablespoon of cornstarch with 2 tablespoons of cold water to create a slurry. Add this cornstarch mixture to the simmering sauce in the skillet, stirring continuously for 1-2 minutes until the sauce thickens to your desired consistency.
Step 5: Remove the skillet from the heat. Garnish generously with chopped green onions for freshness and color. Serve your irresistible Black Pepper Chicken with Mushrooms hot over a bed of steamed rice or your favorite noodles.