Prepare the Onions - Begin by peeling all the pearl onions, which can be a bit tedious but worth the effort. It's highly recommended to wear goggles during this process to prevent your eyes from watering. Once peeled, place all the onions in a 9×13 baking dish, ensuring they are spread evenly.

Create the Seasoning Mix - In a separate bowl, melt the cup of salted butter. Add the minced onions, paprika, lemon pepper, Cajun seasoning, onion powder, garlic powder, and old bay seasoning to the melted butter. Stir thoroughly until all the seasonings are well incorporated into the butter, creating a fragrant, flavorful mixture.

Combine and Cover - Pour the seasoned butter mixture over the pearl onions in the baking dish. Gently toss or stir the onions until each one is fully coated with the butter mixture. Cover the dish tightly with aluminum foil to seal in moisture and flavors during the initial baking process.

Initial Bake - Preheat your oven to 350°F (175°C) and place the covered dish in the oven. Bake for 60 minutes, allowing the onions to become tender while absorbing all the wonderful flavors from the butter and seasonings.

Final Bake and Serve - After the initial baking period, remove the aluminum foil from the dish. Increase the oven temperature to 400°F (200°C) and return the uncovered dish to the oven. Bake for an additional 20 minutes, allowing the onions to develop a beautiful caramelization on the outside. Once done, remove from the oven and serve hot.