Orange Chicken Sauce:

In a medium saucepot, add sugar and orange juice; set over medium heat, stirring occasionally. Bring to a simmer and reduce for 2 minutes. Next, add chili flakes, ginger, and soy sauce; separately, in a small bowl, mix cornstarch and water for your slurry.

Whisk in your slurry, one splash at a time, until your desired thickness. Remove from heat and strain mixture. Optionally finish your sauce by adding garlic.