2 medium zucchini, about 8 oz each, ends trimmed
1 teaspoon grapeseed or canola oil
6 oz skinless chicken breasts, cut into 1/2-inch pieces
Kosher salt and freshly ground black pepper, to taste
1/2 red bell pepper, cut into 1/2-inch pieces
1 teaspoon sesame oil
2 cloves garlic, minced
1 tsp fresh ground ginger
2 tbsp crushed dry roasted peanuts
2 tbsp thinly sliced scallions along diagonal

For the sauce:
1 1/2 tbsp reduced soy sauce (tamari for gluten free)
1 tbsp balsamic vinegar
1 tsp hoisin sauce
2 1/2 tbsp water
1/2 tbsp Sambal Oelek Red Chili Paste (or more to taste)
2 tsp sugar
2 tsp cornstarch