Dice the chicken breast into bite-sized pieces and pat dry with a paper towel.
In a small bowl, toss the chicken with cornstarch, sea salt, and black pepper until evenly coated.
Heat the olive oil in a large skillet or wok over medium-high heat.
Add the chicken to the pan and sear until golden brown and cooked through, about 5-6 minutes, then remove and set aside.
Add the broccoli and sliced bell peppers to the same pan with a tablespoon of water, covering for 2 minutes to steam until tender-crisp.
While vegetables cook, whisk together the honey, tamari, minced garlic, and grated ginger in a small jar.
Return the chicken to the skillet and pour the honey-garlic sauce over the mixture.
Stir-fry for 1-2 minutes until the sauce thickens into a glossy glaze that coats the chicken and vegetables.
Garnish with sesame seeds and serve immediately.