Cooks can use an ordinary bowl and any sturdy, blunt instrument. (The bowl of a ladle will do as a pestle, but make sure to press on the bowl, not the handle, which will snap under pressure, Costa warned.) A spice grinder can be used as well, but it will yield a salt that's more finely textured and less aromatic.
Costa made a variety of salts, and his basic method was the same for all. He'd place about half the salt in the mortar, add fresh ingredients, top with the remaining salt and then grind with his pestle until the mixture looked like coarse sand. (The salt goes below and above the other ingredients because the crystals help with the grinding.)
"A circular grinding motion is significantly more effective than the TV-camera-friendly pounding so often seen on the Food Network," he said.
What Costa added to the salts varied widely, but he kept each blend simple. At most, he added three ingredients to the salt.
He ground lemon with salt for use on chicken, fish, asparagus and salad greens. (Zest of limes, oranges or Meyer lemons works as well.)
For beef, he created a salt with black peppercorns and garlic, blanching the clove beforehand in milk to mellow its bite since the seasoning goes on after cooking.
Rosemary, lavender and blanched garlic were married in a salt meant for lamb or artichokes. Costa chopped the rosemary on a cutting board before grinding to make sure the needles broke down, a step he said helps eliminate "that mouth-drying piney finish." He went light on the lavender because Americans tend to associate the perfume with soap.
"It needs to be a very gentle background note," he said. "Using the rosemary and garlic helps with that. This is a really nice technique when you have fresh herbs right out of the garden."
In the most assertive and exotic salt of the day, Costa used fresh ginger and black garlic, an Asian ingredient that's only recently become available in America. Black garlic is created by subjecting conventional bulbs to a high-heat fermentation process, according to blackgarlic.com. The soft, pitch-black cloves that result have a molasses-y, caramelized aroma.
Grilled pork, beef and lamb are good candidates for that salt. A full-flavored fish like salmon - "maybe, maybe" - could handle this pungent mix, Costa said. Sweet potatoes and carrots can stand up to it, he said with more certainty.
While salt is associated with high blood pressure and other health problems, Costa said people should not shy away from finishing salts.
