Also can be prepared in the oven.
I picked up a box at Costco from the frozen foods section. I believe it's about $12.
1) Put in bowl and microwave (faster/lazier option)
2) Put in bowl and heat in oven (better quality option as you will get what's pictured in the first pic, unlike the third pic which was prepared by a microwave)
I must say that the soup is really tasty. I was quite impressed. I'd take this soup over some that I've had at certain restaurants.
Recommended if you're a fan of French Onion Soup.
Available at Costco.