Hash browns are usually a breakfast thing--crispy and served with eggs. I love what happens when I combine them with other ingredients and bake into a casserole, mixing all the flavors and textures into one delicious cheesy, crispy and creamy bite!
Ensure hash browns are fully thawed and patted dry to prevent a watery casserole; excess moisture is the enemy of crispness here. For the onion, grate it finely and consider gently squeezing out any excess liquid to avoid introducing too much moisture, which can make the casserole soggy. Achieve a truly golden and crispy top by allowing the cheese to brown nicely during the last 10-15 minutes of baking, potentially increasing the temperature slightly if needed. For a richer flavor, a blend of sharp Cheddar and a touch of Monterey Jack or Gruyere could be used. Don't skip the resting time; it helps the casserole set for clean slices.