Cut the chicken breasts into bite-sized cubes. In a mixing bowl, combine all-purpose flour with paprika and garlic salt. Toss the chicken cubes in this mixture and set aside.

Heat 3/4 cup of oil in a large frying pan over medium-high heat. When shimmering, carefully add the breaded chicken in batches and fry for about 3-6 minutes until golden-brown.

In a separate bowl, mix together sugar, water, white distilled vinegar, soy sauce, salt, and red chili pepper flakes until the sugar is dissolved.

Return the crispy chicken to the frying pan and pour the prepared sauce over it. Bring to a gentle boil for 2-3 minutes.

Reduce heat to low and simmer uncovered for approximately 12 minutes, stirring occasionally.

Remove from heat and garnish with sesame seeds or sliced green onions before serving.