The envelope came postmarked Tehran and stuffed with crimson confetti: pure saffron. It came with instructions: crush, seal, steep.

My friend, Charlie, shared the saffron. He shared the instructions. He’s generous like that.

Once I read the note, I knew I was guilty. Previously, I’d rolled the red threads between thumb and finger, I’d tossed the crumbles into stew or sauce, I’d appreciated — but not marveled at — saffron’s sweet-hay scent, its golden glow and bitter bite.

The potent spice — stigmas of the saffron crocus, each hand-plucked and sun-dried — deserves the cook’s full focus. Now I, too, have Charlie to thank.

• 1 bulb fennel with fronds
• 1 clove garlic
• Finely grated zest of 1 lemon
• Kosher salt
• 2 tablespoons olive oil
• 3 cloves garlic, chopped
• 1/2 teaspoon crushed red pepper
• 2 tablespoons tomato paste
• 3 tablespoons steeped saffron (see note)
• 12 ounces waxy potatoes, such as Yukon Gold, cut in 1-inch chunks
• 1-1/2 to 2 cups chicken broth
• 1/3 cup dry white wine
• 20 small clams, scrubbed
• 1/2 cup heavy cream

Snip frilly fronds from fennel. Chop with garlic, lemon zest and 1/2 teaspoon salt to make a gremolata.

Slice fennel bulb into crescents.

In a medium skillet, heat oil over medium. Add fennel crescents, chopped garlic, 1 teaspoon salt and red pepper. Cook, stirring, until vegetables wilt, about 5 minutes. Stir in tomato paste and steeped saffron, then potatoes.

Add enough broth to barely cover potatoes. Bring to boil, reduce to simmer, cover and cook until potatoes are easy to pierce with a skewer, about 10 minutes.

Add wine. Nestle in clams. Cover and steam until clams open, 5-7 minutes. Discard any unopened clams.

Stir in cream. Cover and let rest over low heat, 2 minutes. Scoop into bowls. Dust with gremolata. Serves 2.

Nutritional information unavailable.

Note: To steep saffron, crush at least a tablespoon (better yet, more) to a fine powder (use a mortar and pestle or clean spice grinder). Measure 1/4 teaspoon saffron powder into small jar. Add 3 tablespoons boiling water; steep 30 minutes. Refrigerate any unused elixir, tightly sealed. Seal extra crushed saffron in a jar and store in cool, dark cupboard.