Preheat the oven to 425 degrees F (220 degrees C).
Toss cauliflower with olive oil, 3 teaspoons curry powder, 1 teaspoon garlic powder, 1 teaspoon onion powder, salt, and pepper in a large bowl. Spread mixture in a baking pan.
Bake in the preheated oven until slightly browned, about 25 minutes.
Heat a pan over medium heat. Add chicken, salt, and pepper; stir in the remaining curry, garlic, and onion powders. Cook until browned, 5 to 7 minutes. Transfer chicken to a large bowl; leave pan on heat.
Whisk egg whites with a pinch of pepper. Pour into the pan; cook and stir until eggs are set but still soft, about 3 minutes. Spoon egg whites into the bowl with the chicken; add green onions and the roasted cauliflower rice. Serve fried 'rice' in individual bowls. Add pineapple chunks, a small splash of pineapple juice, and soy sauce to each bowl.