What’s good about secrets? What’s good is knowing them! Vanilla extract is not a secret. Tell us what your secret ingredient is an ingredient in. We don’t keep knowledge secret here; we share it. I demand that you tell us what you put vanilla extract in!
lemon juice - in any cream of something soup, or casserole containing a cream base. It just perks it up and gives it a lively flavor - but not enough so that it tastes lemoney.
Seriously, it’s McCormick’s 1 Step Lemon Herb spice. Put in on almost anything, it’s better. Chicken, fish, veggies, preferably cooked on the grill, rubbed on with a little olive oil. Good stuff.
Liquid Smoke. Especially the Hickory flavor. Gives dips and gravies a real hearty flavor, and is great as a marinade on any kind of grilled meats or vegetables.
For soups and stews, a dash of sage and thyme give a “savory” bouquet. (Parsley and rosemary optional).
Goya adobo all over the chicken before it goes into the oven to bake – lots and lots of it, much more than you’d think would be okay, but it always works, and damn, that skin is crrrrrispy!
Almond extract, in the buttercream icing I make for cake decorating. Used in just the right amount if gives a more distinctive flavor than vanilla, and it’s colorless. Even a small amount of regular vanilla takes a smidge from the whiteness of the frosting. Hard to see, unless you make a lot of it, or have both side by side, but there IS a differenc.
Sriracha chilli sauce. My wife is Vietnamese, and as every Vietnamese household I’ve ever set foot in has a big bottle of this stuff, I’m very familiar with it. It was only later that I found it goes great in western cooking too. It’s generally meant to be used as a condiment at the table, but using it as an ingredient adds a little lift to things such as Bolognese sauce and the like (you don’t get any chilli heat doing this, just a nice flavour).