Prepare the cauliflower: Cut the cauliflower head into bite-sized florets and add them to a large mixing bowl.
Prepare the remaining salad ingredients: Add the cherry tomatoes, bell pepper, red onion, cucumber, mixed beans, fresh dill, crumbled feta, and Kalamata olives to the bowl with the cauliflower.
Make the dressing: In a small bowl or measuring cup, combine the olive oil, white wine vinegar, lemon juice, garlic, Dijon mustard, honey, salt, pepper, and dried oregano. Whisk until smooth and well combined.
Dress and chill the salad: Pour the dressing over the salad ingredients and toss until everything is evenly coated. Cover and refrigerate for at least 1 hour before serving to allow the flavors to develop. Stir once more before serving.