Begin by combining the soy sauce, peanut butter, sesame oil, rice vinegar, garlic powder, cumin, and salt in a bowl, whisking vigorously until the peanut butter fully dissolves into a smooth marinade.

Add the cubed chicken to the marinade, ensuring each piece is well-coated, then cover and refrigerate for 30 minutes to absorb the flavors.

While the chicken marinates, soak wooden skewers in water to prevent burning.

After marinating, thread the chicken and bell pepper cubes alternately onto the skewers, aiming for 4–5 chicken pieces and 2–3 pepper pieces per skewer.

Preheat a grill, grill pan, or oven to 400°F (200°C). If grilling, cook the skewers over medium-high heat for 4–5 minutes per side until charred and cooked through; if roasting, arrange skewers on a parchment-lined tray and bake for 12–15 minutes, flipping halfway.

Serve immediately with extra peanut sauce (optional) and a side of lime wedges or cucumber salad.