Preheat oven to 425°F.
Using a mandolin, slice 350g fingerling potatoes and 2 medium shallots directly into a 9"x13" baking tray. Cover with 2 tbsp olive oil and season generously with salt. Toss to mix.
Pat 4 skin-on, bone-in chicken thighs dry and season all over with salt, at least 1/2 tsp per chicken thigh. Lay the chicken, skin side up, on top of the potatoes and onions.
In a small bowl, whisk together 1 tsp cumin, 1 tsp paprika, 1 tsp onion powder, 1 tsp garlic powder and 1/4 cup olive oil. Pour the spice mixture over the chicken, taking time to rub it on both sides. Finally, sprinkle in 1 tsp coriander seeds.
Transfer the baking dish to the oven (with the chicken skin-side up!) and cook for 40-45 minutes, or until the skin is golden brown and crispy. Remove from oven, transfer to a serving dish, and top with bitter greens. Squeeze 1/2 a lemon all over and serve with additional lemon wedges. Top with some optional feta and serve warm with crusty sourdough bread. Enjoy!
