If I had to keep just one chile on hand, aleppo would be it. After trying it you'll never bother with generic crushed red pepper again. Its flavor is bright and zesty, with a tart fruitiness balanced by an earthy, smoldering aftertaste. I love it most with basic tomato sauces, roasted vegetables, chicken, and nuts.
It's called the Queen of Spices for a reason: To many, cardamom defines the exotic. Its perfume is equally at home in sweet and savory dishes, enhancing the power of herbs and citrus while giving added dimension to white fish and chocolate. It brightens dull flavors like long-cooked meat and bland grains, and can make you look at familiar foods, like chocolate chip cookies, in a whole new light.
I don't know any spice friendlier than coriander. Its subtle flavor is reminiscent of lemon and curry, and it's exceptional with any and all of the following: roast cauliflower, chicken, butter cookies, lentils, squash, soups of all kinds, and all members of the onion family. Occasionally I leave the seeds whole for a sweet crunch. Try adding coriander at the beginning and end of a cooking process—the flavor changes so much it's like two completely different spices.
Grains of Paradise
As far as I'm concerned, black pepper doesn't hold a candle to grains of paradise. It's woodsy, clove-y, citrusy, all with a black pepper kick. I love it in salad dressings and in a dry rub with salt and raw sugar—killer on duck. It's important to have a spice that can be cooked for long periods or cracked fresh at the table. Grains of paradise excel at both.
Fortunately I don't just have to choose one chile for the rest of my life. Paprika is my other all-purpose chile. Hot smoked Spanish is my favorite if you forced me to choose, but I also keep medium-hot unsmoked Hungarian paprika for Eastern European classics. Paprika has a smokey, rounded heat that takes extremely well to aromatic vegetables and all sorts of egg preparations. It excels in small amounts as a background flavor in tomato sauce, soups, and marinades.
Okay, this is kind of a cheat, since niter kibbeh is a blend of curry-like spices cooked into clarified butter. But if you have some in the fridge (and it lasts basically forever), your food will never want for flavor again. Spiced butters like niter kibbeh aren't just a flavor shortcut (though they are that)—they're a spice confit that effortlessly transfers flavor to lentils, chicken, lamb, and beef.
Rich, roasted flavors enter into many dishes: the slight smokiness of wok-fried noodles, crisp-tender roasted or sautéed vegetables, and the charred lines on grilled meat. Sesame seeds bring out those flavors while also contributing crisp, chewy textures and subtle suggestions of citrus and thyme. White seeds taste nutty and are brilliant with butter; black seeds, my favorite, are more savory, a must in stir fries.
Star anise has a licorice flavor of unparalleled headiness, equally home in sticky meat braises and cooked fruit. It's my essential spice for cooking stonefruit and berries of all kinds: in cobblers, compotes, and with ice cream. In very small amounts it can bring out browned, meaty flavors in sauces and stews—perfect for enhancing meaty goodness (or suggesting it when it isn't there).