A mixture of hard-boiled eggs and butter makes a tasty spread for sandwiches, especially when amped up with yogurt, curry powder, jalapeño, and cilantro.
Mash egg yolks with vinegar until smooth. Stir in butter, yogurt, curry powder, jalapeno, and cilantro. Season with 3/4 teaspoon salt and 1/2 teaspoon pepper. Spread on bread, layer with sliced cucumber, and cut into triangles.
For hard-cooked eggs that are creamy and tender, not rubbery, place eggs in a saucepan and cover with cold water by 1 inch. Bring to a boil over high heat; cover and remove from heat. Let stand 8 minutes, then transfer to an ice-water bath.