All-In-One Tuna Casserole

1 each env. golden onion soup mix
1 1/2 cup milk
10 oz frozen peas & carrots *
8 oz medium egg noodles **
6 1/2 oz tuna, drained & flaked
2 oz shredded cheddar cheese ***
* Frozen Peas & Carrots should be thawed.
** Egg Noodles should be cooked and drained.
*** Cheese should equal 1/2 Cup