Tomato Cucumber Salad

1 cup water ½ cup distilled white vinegar ¼ cup vegetable oil ¼ cup sugar ¼ tsp. salt, or to taste 1 tsp. ground pepper, more or less to taste 3 cucumbers, peeled and sliced ¼” thick 3 tomatoes, cut into wedges and then halved 1 onion, sliced and quartered into strips Whisk water, vinegar, oil, sugar, salt, and pepper together in large bowl until smooth. Add cucumbers, tomatoes, and onion and stir to coat. Cover and refrigerate at least 2-4 hours or overnight. Plate and serve cold when ready.