1Sprinkle walnuts in ungreased heavy skillet. Cook over medium heat 5 to 7 minutes, stirring frequently until nuts begin to brown, then stirring constantly until nuts are golden brown.
2In small bowl, stir together oil, vinegar, mustard, salt, sugar and cumin.
3Remove and discard outer leaves of endive. Rinse endive with cold water; pat dry. Cut each endive head diagonally into 1/4-inch-thick slices; place in serving bowl. Add walnuts and parsley. Drizzle with dressing; gently toss to coat. Top with grapefruit. Serve immediately.