Wash and cut 250 grams of broccoli and 250 grams of cauliflower into small florets. Blanch them in boiling water for 2-3 minutes, then drain and rinse under cold water to stop the cooking process. Set aside.
In a large mixing bowl, combine 1 finely chopped medium-sized red onion, 1/2 cup of chopped coriander leaves, and 1/2 cup of chopped mint leaves.
In a separate small bowl, prepare the dressing by whisking together 3 tablespoons of lemon juice, 2 tablespoons of olive oil, 1 teaspoon of honey, 1/2 teaspoon of black pepper powder, and salt to taste.
Add the blanched broccoli and cauliflower florets to the large mixing bowl with the chopped onions and herbs. Pour the dressing over the vegetables and toss well to combine.
Refrigerate the salad for at least 30 minutes to allow the flavors to meld. Serve chilled.