Secret Cooking Ingredients

Calling all those who love to cook. Anyone have a secret ingredient for their special recipes? NO, I am not talking about your special brownies! Yesterday, I made my famous pot roast and as usual, my sons and their friends built in "home cooked meal radar" brought them to my house. Every time I make the roast, we enter the topic of secret ingredients. The secret ingredient to my pot roast is Pepsi, yep Pepsi. I fill the crock pot with Pepsi instead of water (plus one package meatloaf seasoning & onion soup mix). When I make stir fry, my secret ingredient is plum jelly. These secret ingredients are usually undetectable, but the key to someone inevitably saying wow, this is delicious, what is your recipe? Any secret ingredients you're holding out on?