Preheat oven to 350°F (175°C).

Thaw and drain the frozen vegetable combination.

In a large bowl, combine the thawed vegetables, condensed cream of mushroom soup, 1/2 cup of shredded Swiss cheese, sour cream, and pepper.

Add half of the can of French fried onions to the mixture.

Pour the vegetable mixture into a shallow 1-quart casserole dish.

Bake, covered, at 350°F (175°C) for 30 minutes, or until the vegetables are tender.

Remove the casserole from the oven and uncover it.

Sprinkle the remaining Swiss cheese and French fried onions in diagonal rows across the top of the casserole.

Return the casserole to the oven and bake, uncovered, for 5 minutes, or until the onions are golden brown and the cheese is melted.