Preheat the oven to 200 ° C top / bottom heat or 180 ° C hot air. I like to use a hot air grill combination. Let the chicken legs come to room temperature, wash and pat dry. Clean the fennel, removing the stalk, put some of the fennel greens aside and cut into large slices. Peel the onions and cut into rings, wash the lemon and also cut into rings. Place the onion rings on a deep baking tray, then the fennel slices, drizzle with a little olive oil, season with salt and pepper and top with the lemon slices. First place the chicken legs on the vegetables with the inside facing up, season with salt and pepper and bake in the oven for about 20 minutes. Then turn the thighs, season with salt and pepper again and bake for another 20-25 minutes, until the skin is nice and crispy. If necessary, help a little with the grill function. Finally, chop the set aside fennel greens and sprinkle over the meat and vegetables just before serving. Note: If you don`t do SiS or Paleo, you can eat some rice or baguette with it - if necessary, increase the number of people or reduce the number of chicken legs.