1. Chop the leek. De-stem and finely chop the kale. Zest lemon and orange.
2. Heat half of the oil in a very large saucepan or wok over medium heat.
3. Add the leeks, garlic, and salt and sauté, stirring constantly, for about 4 minutes, or until the leek begins to soften.
4. Add the rice to the pot and stir until coated with a nice sheen, then add the white wine and simmer for 3 or 4 minutes, until the rice has absorbed the liquid a bit.
5. Add the chicken broth 1 cup at a time to the saucepan, stirring occasionally to prevent sticking, until all of the liquid is used and absorbed.
6. When rice is tender and no liquid remains: Into the remaining risotto, stir in the greens, the remaining oil, lemon zest, and orange zest.
7. Season with salt and pepper to taste.
8. Spoon the risotto into bowls; top with tarragon.