A lot of people focus, when they talk about their own recipes – the recipes they have created, or modified from already-existing dishes – on secret ingredients. There’s that one, singular item you add to “make it your own,” (or, if you’re the Colonel, maybe eleven). If you’re a certain kind of cook, you leave it out of your written recipes so no one can duplicate your masterpiece exactly, and they struggle for a lifetime trying to figure out why theirs doesn’t taste quite like yours. Secret ingredients puzzle your audience; they are intrigued but can’t quite identify that flavor combination – it blends just enough to keep it unidentifiable.

My one big secret ingredient used to be nutmeg in oatmeal chocolate chip cookies – it added another layer of warmth and interest, and it made one of my high school friends giggle about my cookies being aphrodisiacal. It was unexpected until you knew it was there, and then it made sense. My college roommate adopted it in her own chocolate chip cookies and at least once left it out of the recipe she passed along to a friend, so that the cookies would never be quite the same, thereby keeping them special.

Apart from that, my typical “secret ingredient” practice is just adding so many components that I likely won’t remember them all when I need to recreate whatever dish it was (clearly ideal methodology for a food blogger!). But suddenly, I have a secret ingredient. It fits all the qualifications: it adds a definite flavor without being obvious, and it would be difficult to guess at were you trying blindly to taste out every component of the dish.

This came about by accident, as many of my masterworks do. We had just arrived home from our annual summer road trip, which meant a whatever-is-still-good meal. Pasta is easy here – a bag of spaghetti and a can of tomatoes are guaranteed to be fine and tasty – but being who I am, the urge to tinker kicked in and I was rooting around in the fridge looking for something to make it special. I found a container of heavy cream that, shoved to the very back, was not only still good, but almost frozen, and a tiny, hard, crusty little corner of miso paste. It looked okay, apart from being approximately the texture of granite, and in a moment of innovation genius “well, why not?” I tossed it into the sauce.

As secret ingredients go, this is a good one. No, you don’t necessarily want to buy a whole tub of miso paste just for this, since you’ll only be going through a tablespoon or two, but the number of other sauces, soups, and stir-fry dishes that it will contribute to makes it a great thing to have at the back of the fridge. (And really, if you bought the stuff for Deb’s recipe in the first place, you’ll need a new recipe to use up that last stubborn chunk that has been hiding in your fridge for months anyway.) The miso adds all the salt needed to the sauce, but it also contributes a lux, complex quality that gives depth the tomatoes and somehow makes the cream feel lighter – more sprightly.

In the final incarnation, I added leeks for an onion-y aromatic base, a splash of wine to deglaze, and a smattering of chili flakes, and I was delighted with all of these additions, though you could certainly leave out the heat, replace the leeks with garlic or shallot (or some combination), and I wouldn’t say no to marsala in place of the wine.

In any case, though, scatter the top with a chiffonade of basil or some parsley fragments, and challenge your dinner guests to guess what that extra flavor is – I bet they will be stumped, trying to determine our new secret ingredient.

Spaghetti with miso tomato sauce

40-45 minutes

Serves 8-10

1 pound spaghetti

2 tablespoons salt for pasta water

4 tablespoons butter

½ cup finely chopped leek, white and pale green parts only

½ cup dry white wine

¼ teaspoon red pepper flakes (or to taste)

2 tablespoons white or red miso paste

28 ounce can whole peeled tomatoes

½ cup heavy cream, at room temperature (adding to the sauce at room temperature, rather than cold, eliminates the danger of curdling)

optional: 2-3 tablespoons chopped parsley or chiffonade of basil to scatter over the top

• Fill a large pot with water, add the 2 tablespoons salt, and bring to a boil. When it boils, add the spaghetti and cook according to package directions, stirring once or twice to separate pasta strands. When the spaghetti is tender but still has a slight bite, drain it and add it to the sauce as directed below.
• While the pasta water heats, melt the butter in a large skillet over medium heat. When it is melted, add the leeks and turn the heat down to medium-low; sweat the leeks, stirring often, until they are tender. This should take about 8-10 minutes.
• When the leeks are tender and translucent, add the wine and the red pepper flakes, stir to integrate, and raise the heat to medium-high. Simmer for 3-5 minutes to cook off some of the raw flavor of the wine.
• Now, add the miso paste, using a wooden spoon or a whisk to break it up and integrate it evenly into the wine mixture. Cook 2-3 minutes to allow it to soften and distribute (the older the miso paste is, the more reluctant it will be to integrate).
• Dump in the canned tomatoes and their juice, stir, and turn the heat down to medium-low. Simmer for 20-30 minutes, stirring occasionally. Periodically, crush the tomatoes with the back of a wooden spoon or with a potato masher (be careful: they squirt!).
• When the sauce has simmered at least 20 minutes to let the flavors blend, and when the pasta is cooked and drained, take the skillet off the heat and stir in the room temperature cream.
• Integrate the drained pasta (I use tongs for this), then place the skillet back over medium-low heat and cook, frequently manipulating the pasta with your tongs, for another two minutes. This lets the pasta absorb some of the sauce.
• To serve, transfer to a large bowl or serving dish and, if desired, scatter the top with your parsley or basil. Warm garlic toast is a welcome accompaniment.