Whisk together 3 tablespoons soy sauce, 3 tablespoons lime juice, 2 tablespoons Sriracha, 1/4 cup sugar-free maple syrup, 3 tablespoons Golden Monkfruit sweetener, 1 tablespoon minced garlic, and 1 teaspoon sesame oil in a mixing bowl to make the marinade.
Trim fat from the chicken breasts and cut each into chunks (about 8 pieces per large breast) so you have roughly 24 pieces total for 4 servings.
Place the chicken pieces and 1/2 cup of the marinade into a resealable bag or container; refrigerate and marinate 6–8 hours or overnight. Reserve the remaining marinade in the refrigerator.
When ready to cook, preheat the oven to 425°F (218°C) and place a sheet pan in the oven to heat.
Drain the marinated chicken in a colander and let it drain very well, pressing gently if needed to remove excess liquid.
Combine the reserved marinade with 1/4 cup sugar-free orange marmalade and the remaining 1 tablespoon soy sauce, then blend until smooth in a blender or food processor to make the glaze.
Trim the ends from the green beans and cut them in half; toss the beans with 1–2 tablespoons of the glaze to coat.
Remove the hot sheet pan from the oven and lightly spray it with nonstick spray. Arrange the green beans in a single layer and tuck the drained chicken pieces among them, spacing the pieces evenly.
Brush the chicken and beans with half of the remaining glaze and bake for 10 minutes at 425°F (218°C).
Remove the pan and blot any released liquid with a paper towel if needed, then brush with the remaining glaze and return to the oven. Bake 10 minutes more, until chicken is cooked through and beans are tender-crisp.
Remove from the oven, blot excess liquid if present, sprinkle with toasted sesame seeds, and serve hot.