Pat the chicken breast dry with a paper towel and cut into 1-inch cubes.
In a medium bowl, toss the chicken cubes with arrowroot powder, sea salt, and black pepper until evenly coated.
In a small glass jar or bowl, whisk together the honey, tomato paste, rice vinegar, and tamari until the sauce is smooth.
Heat the avocado oil in a large non-stick skillet or wok over medium-high heat.
Add the chicken to the skillet in a single layer and sear for 3-4 minutes per side until the edges are crispy and golden brown.
Add the sliced red bell peppers and pineapple chunks to the pan, sautéing for an additional 3 minutes until the peppers are crisp-tender.
Pour the prepared sauce over the chicken and vegetables, stirring constantly for 1-2 minutes until the sauce thickens and glazes the ingredients.
Remove from heat and garnish with sesame seeds before serving.