Bring a medium pot of salted water to a boil. Add the broccoli florets and cook for 4 minutes until crisp-tender. Drain and set aside.
Line a large baking sheet with a wire rack. Set aside.
In a large mixing bowl, whisk together the flour, cornstarch, 1½ teaspoons salt, and pepper. Add the chicken and stir vigorously to coat.
Heat a ¼-inch layer of neutral oil in a deep skillet or medium saucepan set over medium-high heat. Working in batches to avoid overcrowding, add the chicken and cook for about 4 minutes, undisturbed. Flip and cook for about 4 minutes more until the chicken is browned and cooked through. Transfer the cooked chicken to a paper towel-lined plate. Repeat with the remaining chicken.
In a large wok or skillet, cook the sesame sauce over medium-high heat until thick, about 2 minutes. Reduce the heat to medium-low and add the blanched broccoli and cooked chicken. Cook, stirring for about 2 minutes, until the sauce coats the chicken and broccoli evenly. Taste and season with salt, if needed.
Serve over jasmine rice (if using), and garnish with scallions, sesame seeds, and chili crisp (if using).
