1 pound fresh sea scallops, cut into 1/4- to 1/2-inch dice

2 plums, pitted and cut into

1/4- to 1/2-inch dice

1 to 2 teaspoons chopped fresh tarragon, or more to taste

1/4 cup freshly squeezed lime juice

1/2 teaspoon grated lime zest

Salt

Pinch cayenne pepper.