Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.

In a large mixing bowl, combine the cream of mushroom soup and vegetable stock. Stir until well blended.

Add the thawed and drained frozen vegetables to the soup mixture. Mix to combine.

Sprinkle the Italian herbs seasoning and garlic salt over the vegetable mixture. Stir to evenly distribute the seasonings.

Gently fold in the shredded cheddar cheese until it's well incorporated.

Finally, add the cooked brown or long-grain rice to the mixture and stir until everything is evenly coated.

Transfer the mixture to the prepared baking dish, spreading it out evenly. Top with cornflakes.

Cover the baking dish with aluminum foil and bake in the preheated oven for about 30 minutes. This allows the casserole to heat through and the flavors to meld.

After 30 minutes, remove the foil and bake for an additional 10-15 minutes or until the top is golden and bubbling.

Once the casserole is done, remove it from the oven and let it cool for a few minutes before serving.

Serve your Cheesy Vegetable Rice Casserole as a delicious side dish or a comforting main course.