Preheat oven to 450 degrees.
Line a rimmed baking sheet with parchment.
Toss cherry tomatoes in olive oil, spreading on prepared baking sheet.
Sprinkle with salt.
Roast for 20 minutes, until skins blister and burst.
Let cool.
Rinse and drain lettuces.
In a large salad bowl, add lettuces, cucumber, red pepper, red onion and olives.
In a small bowl, add red wine vinegar, dijon, garlic, oregano, salt and pepper whisking, until well-combined.
Slowly add olive oil, whisking, until emulsified.
Drizzle dressing over salad mixture, tossing to combine. *
Top with feta and fresh oregano.
* Dress to desired taste — leftover dressing will keep for one week refrigerated. Bring to room temperature & whisk before re-serving.