Bring a pot of salted water to a boil. Cook ditalini pasta for 8-10 minutes until al dente, then drain and cool under cold water.

Fry bacon in a skillet for 6-8 minutes until crispy. Transfer to paper towel to cool and crumble.

In a salad bowl, combine chopped romaine, iceberg lettuce, red cabbage, grape tomatoes, and green onions.

Add cooled pasta and crumbled bacon to the salad bowl. Mix in cooked chicken if using.

Whisk together olive oil, vinegar, garlic, mustard, sugar, oregano, salt, and pepper in a mixing bowl. Adjust seasoning as needed.

Drizzle dressing over salad and toss gently before serving.