Preheat oven to 375°F (190°C).
Cook rice in vegetable broth until fluffy, about 15 minutes.
Sauté vegan chicken strips lightly if desired for extra flavor.
In a saucepan, melt vegan butter over medium heat; whisk in flour to form a roux.
Gradually whisk in almond milk; cook until thickened.
Add vegan cheddar, mustard powder, salt, and pepper; stir until smooth.
Combine cooked rice, vegan chicken, vegetables, and cheese sauce in a baking dish.
Bake uncovered for 25 minutes until bubbly and lightly golden on top.
Let rest 5 minutes before serving for perfect creamy texture.