In a medium bowl, whisk together chicken broth, sugar, and cornstarch until the mixture is smooth. Do this at the start of prep so that it is ready to go when you need it later.
Dredge & Fry Chicken
To make the dredging mix, combine the flour, curry powder, salt, chili flakes, and garlic powder in a resealable plastic bag or study brown paper bag.
Pat chicken breasts dry. You don't want a lot of extra moisture on them when they are tossed in the dredging mix.Slice the chicken into strips - ¾-inch wide by 2-inch long, give or take.
Toss the cut chicken strips into the bag one at a time, and then shake a few times to coat everything evenly. Avoid adding the chicken all at once, because it will stick together when it hits the flour mixture.
Heat a large, heavy skillet over medium heat. Add 2-3 tablespoons of butter and melt just until it begins to bubble. Swirl to coat the bottom of the pan evenly.
Brown half of the chicken pieces in the melted butter, turning with tongs as needed so they brown on two sides; 3-4 minutes total. (The chicken does not need to be fully cooked at this time.)Remove the chicken from the pan as it browns, and set it aside. Repeat, browning the remaining chicken in the remaining butter.
Make Lemon Sauce
When the chicken is done cooking, immediately add the sliced mushrooms to the empty skillet. Add a little more butter if necessary.Sauté until the mushrooms soften and begin to brown.
Reduce the heat to medium-low. Add the wine and stir frequently until it has evaporated, deglazing the pan as you do.
Simmer & Serve
Whisk up the chicken broth mixture and add it to the pan with the mushrooms. Add the browned chicken strips, lemon zest, lemon juice, and chili flakes. Stir once to evenly combine.
Bring the mixture to a low simmer and then reduce heat to low. Cover and simmer for 2-4 minutes; until the the chicken is no longer pink and the sauce has thickened slightly.
Stir in the green onions and sesame seeds, reserving some for garnish if desired. Serve over hot rice or noodles.
Nutrition information includes values for chicken and sauce. It does not include values for any rice or noodles.