Arrange the orange slices on the bottom of the crock pot in one layer.
In a large plate or a mixing bowl, combine flour, lemon zest, salt and pepper; toss the chicken in the flour mixture.
Add chicken to the crock pot in one single layer.
In a small mixing bowl combine sweet chili sauce, soy sauce, lemon juice, and garlic; mix well until thoroughly incorporated.
Pour the prepared sauce over the chicken and brush it all around the pieces.
Cover the crock pot and cook on low for about 4 to 5 hours, or until chicken is cooked.
Uncover and gently stir; let stand 10 minutes.
Garnish with slices of green onions and sesame seeds.