In a medium bowl, mix soy sauce, tomato sauce, peanut oil, garlic, pepper, and cumin. Place prepared chicken (or shrimp; if using both, use a separate bowl and divide the marinade in half) into the mixture. Stir to coat all pieces. Cover and marinate in the refrigerator for at least 15 minutes, but about an hour is plenty.
Preheat the grill to high heat.
While the grill is preheating, prepare the sauce. Spray a medium nonstick skillet with cooking spray and place over medium heat. Add the onion and garlic and sauté until lightly browned about 5–6 minutes. Mix in the water, peanut butter, and a tablespoon of soy sauce. Cook and stir until well-blended, about 2–3 minutes. Remove from heat and mix in the lemon juice. Pour into a serving bowl for dipping and set aside.
Thread chicken/shrimp onto skewers and discard the marinade. Grill skewers for about 5 minutes per side until chicken/shrimp is cooked through. Place on a serving platter or separate plates and serve with peanut sauce.
THE REBELLIOUS RD
As a longtime promoter of healthy cooking and eating, Amy's focus is on plant-based eating, with a rebellious twist - that she and no one, needs to be perfect.