Bring a small pot with rice and 1 1/2 cups of water to a boil. Reduce to a simmer, cover, and cook until rice is tender, 20 minutes. Thoroughly rinse produce and pat dry. Core and cut red and green bell peppers into 1” dice. Trim and thinly slice top 2” of green part of green onion for garnish and slice remaining green onion into 1” lengths. Halve grape tomatoes. Rinse chicken breasts, pat dry, and, on a separate cutting board, cut into 1.5” dice. Season chicken with a pinch of salt and pepper and reserve.

Warm a medium pan over medium-high heat. Add 1 tsp. olive oil and diced peppers to hot pan and cook 2 minutes. Add green onion (reserving thinly sliced pieces for garnish), tomatoes, and pineapple (including any juice) to pan and cook 1 minute. Add sweet and sour sauce, season to taste with salt and pepper, and reserve.

Heat canola oil in a medium pan over medium heat to 350 degrees. Combine batter mix and just enough cold water (about a cup) to form a loose batter in a mixing bowl. (Batter should be thinner than pancake batter.) Add chicken pieces to batter and toss to coat completely.

Test oil temperature by adding a pinch of batter to it. It should sizzle gently. If it browns immediately, turn the heat down and let the oil cool. Working in 2 batches, lay chicken away from you in hot oil and cook 7-9 minutes, turning occasionally, until golden brown. When chicken has reached a minimum internal temperature of 165 degrees, remove from oil and set on a paper towel-lined plate. Let oil recover for 1 minute and come back up to temperature between batches.

Transfer cooked chicken to pan with sauce and vegetables and toss. Season to taste with salt and pepper.

Place a portion of rice in the middle of a plate and arrange chicken and sauce around the rice. Garnish with remaining green onions and serve immediately.