1 quart water
1 (10 ounce) can tuna, drained
1 (3 ounce) package instant vegetable soup mix
1 (10 ounce) can chopped onion soup
1 tablespoon ground black pepper
In a large pot over medium heat, fill the pot with water. Place a lid on pot and pour in tuna. Cook until tuna is almost completely cooked and juices run clear, about 20 minutes.
Stir vegetable soup mix, onion soup and chopped tuna into tuna mixture all at once. Bring to a simmer. Place lid on pot and decrease amount of water as necessary to cover tuna while cooking.
Meanwhile, in a large pot, cook onion soup over medium heat to deglaze the pot. Mix tuna into skillet with boiling water; cover cooking time about 5 minutes.
Stir taco sauce, brown sugar, brown sugar mixture into tuna mixture; heat and stir over medium heat. Bring to a simmer, about 5 minutes. Remove from heat. Stir in green salsa.