Cook pasta according to directions on package. Allow to cool completely before combining with salad ingredients.
For the vinaigrette, whisk together mustard, vinegars, olive juice, lemon juice, zest (optional) oregano, salt, pepper, honey and garlic. Stream in olive oil while whisking until dressing is emulsified.
Place endive or lettuce (optional) in bottom of serving dish.
In a separate bowl, combine cucumbers, tomatoes, and onions. Add a pinch of salt and pepper to enhance flavor.
Dress vegetables with half of the vinaigrette. Add olives, red bell peppers, half of the feta, and pasta. Toss to combine thoroughly.
Assemble the mixture on top of the bed of greens. Top with the remainder of the feta and a drizzle of more dressing or olive oil. Allow to rest for 15-20 mins and serve.