Start by washing the radishes thoroughly under cold water. Pat them dry with a clean towel.
Using a sharp knife or julienne peeler, thinly slice the radishes into even rounds. Aim for as thin as possible to help them marinate quickly and evenly.
In a small bowl, whisk together the fresh lemon juice, honey or agave syrup (if using), and a pinch of salt. Whisk until the mixture is smooth and slightly frothy.
Pour the lemon dressing over the sliced radishes in a large mixing bowl. Use tongs or two spoons to toss the radishes gently, ensuring each slice is coated with the tangy dressing.
Let the radishes sit for about 5 minutes. This allows the slices to soften slightly and soak up the bright lemon flavor, enhancing their crispness and zing.
Taste the salad and adjust the seasoning with more salt or pepper if needed. For an extra burst of freshness, add chopped herbs just before serving and toss lightly to combine.
Transfer the salad to a serving plate or bowl. Drizzle with a tiny splash of olive oil for a glossy finish, if desired, and serve immediately to enjoy the crisp texture and vibrant flavors.