Deviled Eggs with mayonnaise

6 hard-boiled eggs 2 tablespoons extra-virgin olive oil 1 tablespoon mayonnaise 1 1/2 teaspoons Dijon mustard 2 tablespoons minced celery 4 teaspoons chopped[...]

2 tablespoons butter 2 tablespoons olive oil 1 large Spanish onion , diced small 1 teaspoon sugar 12 eggs 1 cup nonfat yogurt , plain, Greek style, drained 1[...]