I start by preheating my oven to 350°F and lightly greasing my baking dish with butter or nonstick spray. This step keeps the casserole from sticking to the edges once it's baked. It only takes a minute, but skipping it makes cleanup so much harder later.
In a large bowl, I combine the shredded chicken, cooked rice, sour cream, cream of chicken soup, and chicken broth. I stir it slowly so the rice doesn't break apart too much. This forms the creamy backbone of the whole casserole.
Next, I fold in the peas and carrots along with the garlic powder, onion powder, salt, and pepper. I taste the mixture at this point and adjust the seasoning if it needs more punch. This is where the flavor really starts coming together.
I stir about half of the shredded cheddar directly into the mixture so it melts throughout the casserole. I save the rest of the cheese for topping later, which gives you that gooey, cheesy layer people love.
I spread the mixture evenly into my prepared baking dish, smoothing the top with a spatula. Getting an even layer helps the casserole cook consistently instead of leaving some spots dry and others underdone.
In a small bowl, I toss the crushed crackers with melted butter until every piece is coated. This step is what creates that golden, crunchy crust everyone fights over at the table.
I sprinkle the remaining cheddar over the casserole, then scatter the buttered cracker crumbs on top. I bake it uncovered for about 30 to 35 minutes, until the edges are bubbling and the topping turns a deep golden brown.
Once it's out of the oven, I let the casserole sit for about 5 minutes before serving. This short rest helps the filling set slightly so it holds together better when you scoop it.