1-Step 1: Preheat and Prepare Your Baking Dish Start by preheating your oven to 325 degrees Fahrenheit. This lower temperature is intentional – it allows the casserole to heat through gently without drying out or over-browning the cheese on top. While the oven warms up, grease an 8×8 inch square baking dish or a similar-sized round casserole dish with a little butter or non-stick cooking spray. This prevents sticking and makes serving much easier. I like to use a glass dish because it lets me see how the cheese is browning on the edges, but any oven-safe dish will work just fine.

2-Step 2: Prepare Your Ingredients Before you start mixing, it helps to have everything prepped and ready to go. Take your cream cheese out of the refrigerator and let it soften – this is important because cold cream cheese will leave lumps in your casserole. If you’re short on time, you can microwave it for about 15-20 seconds to speed things along. Shred your cheeses if you bought blocks, dice the celery into small, even pieces (about 1/4 inch), and slice your green onions, keeping the white and green parts separate. Flake apart your imitation crab meat into bite-sized pieces if it came in larger chunks.

3-Step 3: Mix the Base In a large mixing bowl, combine all your main ingredients. Add the imitation crab meat, half of the mozzarella cheese (that’s 1/4 cup), half of the Colby Jack cheese (another 1/4 cup), diced celery, sour cream, white parts of the green onions, softened cream cheese, mayonnaise, Worcestershire sauce, lemon juice, and garlic salt. Using a spatula, stir everything together until well combined. You want the cream cheese and sour cream to be evenly distributed throughout the mixture, coating all the crab and vegetables. Don’t worry about being too gentle – the imitation crab can handle some mixing without falling apart completely. The mixture should be thick and creamy with visible pieces of crab, celery, and onions throughout.

4-Step 4: Transfer to Baking Dish Spoon the mixture into your prepared casserole dish, spreading it out into an even layer. Use your spatula to smooth the top so everything bakes evenly. The casserole won’t rise much during baking, so whatever thickness you have now is roughly what you’ll end up with. An 8×8 dish gives you a thicker casserole with more substantial servings, while a larger dish will give you a thinner layer that heats through faster.

5-Step 5: Add the Cheese Topping Now for the best part – sprinkle the remaining mozzarella and Colby Jack cheeses evenly over the top of the casserole. This cheese layer will melt and brown during baking, creating that gorgeous golden top that makes this dish so appealing. Make sure to cover the entire surface evenly so every bite has that delicious cheesy topping. Some people like to add a little extra cheese because, well, you can never have too much cheese in a casserole like this.

6-Step 6: Bake Until Golden and Bubbly Place the casserole in your preheated oven and bake for 20 minutes. You’ll know it’s done when the cheese on top is melted, golden brown in spots, and bubbling around the edges. The internal temperature should reach about 165 degrees Fahrenheit to ensure it’s heated all the way through. Every oven is a little different, so start checking around the 18-minute mark. If you want a more browned top, you can pop it under the broiler for 1-2 minutes at the end – just watch it carefully so it doesn’t burn.

7-Step 7: Finish and Serve Remove the casserole from the oven and let it rest for about 5 minutes before serving. This brief rest helps the cheesy topping set slightly so it doesn’t slide right off when you scoop it out. Sprinkle the green parts of the green onions over the top for a fresh pop of color and a mild onion bite. Serve warm and enjoy that creamy, cheesy, seafood goodness! This casserole pairs well with steamed rice, a simple green salad, or roasted vegetables for a complete meal.