Rita Moreno took a deep, languorous inhale. “I love this smell,” she said. “Can you smell this? It’s an unusual smell.”

The famed actress of stage and screen had just poured ruby red annatto seeds into an oversize pan. After allowing them to sizzle for a few minutes, she used a slotted spoon to fish them out, leaving a rust-colored oil behind. “Now we can do some frying,” she said, raising her eyebrows with excitement.

It was a mild Sunday afternoon, and Ms. Moreno was demonstrating her kitchen chops at the Midtown Manhattan apartment of Jamie deRoy, a Broadway producer. Around her was a four-person documentary crew, there to film her for a coming episode of “American Masters,” the PBS show that chronicles the lives of artists.

She was making picadillo, a stewlike dish of ground beef, peppers, olives and raisins. “It means chopped up,” she said, surrounded by small piles of diced ingredients. “First, let’s put in the onions and the garlic.”