Thinly slice the red onion into half-moons until you have about 1/4 cup. If onion is strong, soak slices in cold water 5 minutes then drain and pat dry.

Core and dice the tomatoes into 1/2-inch pieces to yield about 1 1/2 cups. If using cherry tomatoes, halve them.

Peel the cucumber if desired, then slice lengthwise and cut into 1/4-inch half-moons to yield about 1/2 cup. Pat cucumber pieces dry to avoid watering down the salad.

Place the dried salad greens in a large bowl. Add the tomatoes, cucumber, and onion. Sprinkle the chopped parsley (if using), 1/4 tsp salt, and 1/8 tsp black pepper over the salad and toss gently to combine. Set aside while you make dressings.

Ranch Dressing

In a small bowl or jar, combine 1/2 cup mayonnaise and 1/4 cup sour cream. Whisk until smooth.

Add 1/4 cup buttermilk and whisk to thin to desired consistency. For thicker dressing use less buttermilk; for thinner, add up to 2 tablespoons more.

Stir in 1 tablespoon finely chopped chives, 1 teaspoon chopped fresh dill, 1/2 teaspoon minced garlic, 1 teaspoon lemon juice, 1/4 teaspoon salt, and 1/8 teaspoon black pepper. Taste and adjust seasoning.

Cover and refrigerate at least 15 minutes to let flavors meld. If dressing thickens too much, thin with a little additional buttermilk or water before serving.

Balsamic Dressing

In a small bowl or jar, whisk together 1 tablespoon balsamic vinegar, 1/2 teaspoon dijon mustard, 1/2 teaspoon honey (optional), and 1/4 teaspoon minced garlic until combined.

Slowly whisk in 3 tablespoons extra-virgin olive oil until the dressing emulsifies. Season with 1/8 teaspoon salt and 1/8 teaspoon black pepper. Taste and adjust acidity or sweetness as needed.

Transfer to a serving container. Shake or whisk again just before dressing the salad.