Preheat vegetable oil in a saucepan to 350*. You will want about 3 inches of oil so adjust the amount of vegetable oil based on the size of the pan.
Cube the chicken. Then, create a dredging station for the chicken. Gather 3 bowls. Add cubed chicken to one bowl. Whisk the eggs with a pinch of salt and pepper in a second bowl. In the third bowl, stir together the cornstarch and flour.
Dip the chicken into the flour mixture, then into the eggs, and back into the flour. Then, add chicken to the hot oil. Fry for 5 minutes. ** Do not add all the chicken pieces at once, only enough that they are not touching as they fry. You may need to do a couple batches. This is to prevent the chicken from sticking to each other. **
Chop broccoli into florets and place into a bowl. Add ¼ cup water, cover, and microwave for 3 minutes.
In a medium mixing bowl, whisk together chicken broth, sriracha, hoisin sauce, and soy sauce. Then, stir together 1 tbsp of cornstarch with 1 tbsp cold water and add to the bowl. Pour mixture into a wok and heat on medium high heat. Stir in red pepper flakes, garlic, and brown sugar. Cook for 5 minutes.
Add chicken and broccoli to the wok and toss to coat. Cook for 5 more minutes and remove from heat. Top with chopped green onions and sesame seeds and enjoy!
Cut the chicken into similar sized pieces so that they cook through evenly.
The quickest way to cook the broccoli before adding it to the sauce is in the microwave, but you can steam or boil it.
I like to use vegetable oil for frying, but any high heat oil will work well.