Scrub the watermelon radishes. Thinly slice with a mandolin or sharp chef’s knife.
In a medium bowl, combine the white wine vinegar, cane sugar, and sea salt. Add the radishes, making sure that the slices are well coated. Set aside and let marinate for 30 minutes or up to 24 hours refrigerated.
Wash the kale and cut off the tough stems. Slice the kale chiffonade (into ¼ inch ribbons). In a large bowl, whisk together the oils, lemon juice and fresh herbs. Season to taste with sea salt and fresh pepper. Add the kale to the bowl and massage and mix with your hands until the leaves are well coated and start to soften.
To serve the salad, drain the radishes. Line a platter with some watermelon radish slices, mound the kale over and garnish with more radishes. Sprinkle the top with the toasted seeds and serve.