Start by cooking your instant rice according to the package instructions. Meanwhile, finely dice the onion. If you're using fresh broccoli, cut it into small florets.
In a skillet, heat the olive oil over medium heat. Add the diced onion and sauté until softened and translucent. This should take about 5 minutes.
In a large mixing bowl, combine the sautéed onions, cooked rice, creamy chicken soup, shredded cheddar cheese, broccoli florets, melted butter, garlic powder, and red pepper flakes. Stir everything together until well combined.
Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking dish. Pour the mixture into the dish, spreading it evenly.
In a separate bowl, mix the crushed Ritz crackers with a little melted butter. This will help the topping achieve that perfect golden crispiness. Sprinkle the cracker mixture over the casserole.
Place the casserole in the preheated oven and bake for 30 minutes, or until it’s bubbly and golden on top.
Once out of the oven, let it cool for a few minutes. This makes it easier to serve. Enjoy it as a side dish or on its own!