1) Preheat oven to 425 degrees Fahrnheit.
2) In a bowl, combine pancake mix, mayonnaise, broth, and mustard until creamy.
3) Drain and rinse green beans and peas. Spread in a casserole dish with the dried onions and cover with batter mixture. Cook for 25 minutes or until casserole is set and edges are brown.
This was created as a means to empty the pantry, so I highly recommend experimenting with other ingredients. I think it would be awesome with corn.