Seafood and Cauliflower Gratin

Preheat the oven to broil.

In a large saucepan, bring salted water to a boil.

Add the cauliflower florets and cook for 4 minutes.

Drain and rinse under cold water to stop the cooking process.

Set aside.

In the same saucepan, melt the butter over medium heat.

Add the chopped onion and cook for 1 minute until softened.

Stir in the flour and cook for another minute, stirring constantly to avoid clumps, without letting it brown.

Gradually pour in the milk while whisking constantly to prevent lumps from forming.

Continue cooking and stirring until the mixture thickens and just begins to simmer.

Add the thawed shrimp, scallops, cooked cauliflower, and chopped chives to the sauce.

Season with salt and pepper to taste.

Heat through for 2 to 3 minutes.

Transfer the seafood and cauliflower mixture to a 13 x 9-inch baking dish, spreading it out evenly.

Sprinkle the shredded mozzarella cheese over the top.

Place the baking dish in the center of the preheated oven and broil for 8 to 10 minutes or until the cheese is melted and golden brown.

Remove from the oven and let it cool for a few minutes before serving.