Preheat oven to 400. Blend together pineapple, water, soy sauce, water, ginger, and garlic. Bring to a boil in a medium saucepan and simmer until thickened, about 5 minutes.
Add rice to 2 cups boiling, salted water. Cover, bring to a simmer, and cook for 18 minutes. Meanwhile, cook cauliflower rice in the microwave for 4 minutes. Mix into cooked rice.
Spread chicken on one sheet pan (lined with parchment or tin foil) and toss with 2/3 cup of sauce. Toss veggies on a separate sheet pan toss with 2/3 cup of sauce. Bake chicken for 20 minutes, flipping and tossing with sauce once. Add in veggies when you have 10 minutes cook time left. .
Divide everything between 6 meal prep bowls. Per bowl, mine came out to about 3/4 cup rice mixture, 2/3 cup veggies, and 1/2 cup chopped chicken. I drizzled leftover sauce evenly over the bowls.