Drain pineapple, reserving juice. Set chunks aside. Combine pineapple juice, cornstarch, chili powder, tomato paste, cayenne, honey, vinegar, bragg and garlic. Set aside.
Heat oil in a large skillet over medium high heat. Add bell peppers and onions. Cook, stirring frequently, 2-3 min or until peppers are tender-crisp. Add shrimp. Cook about 3 min or until shrimp are cooked through.
Stir the sauce and immediately add to shrimp mixture in skillet. Add pineapple. Cook, stirring occasionally, until mixture is thickened and bubbly, about 5 minutes. Serve over cooked brown rice.
Feel free to use fresh pineapple in place of canned. You'll need 1-2 cups depending on how pineapple-y you like it. You'll also need about 1/2 cup pineapple juice (not from concentrate).