Whisk together flour, baking powder, coriander, cardamom, turmeric, cinnamon, and nutmeg in a bowl. Season with salt and pepper. Whisk together eggs and 1/4 cup water in a separate bowl. Place grits in a third bowl.
Preheat oven to 250°F. Place a rack inside a rimmed baking sheet and place in oven. Heat canola oil in a large skillet over medium heat. Season chicken with salt and pepper. Working in 3 batches, coat chicken in flour, then egg (letting excess drip off), and then grits (pressing gently to help adhere). Cook until golden brown and cooked through, 3 to 5 minutes per side. Transfer to prepared rack to keep warm.
Heat olive oil in a large cast-iron skillet over medium-high heat. Add green beans and cook, without stirring, until beans start to brown and blister, 4 to 5 minutes. Season with salt and pepper and continue cooking, tossing occasionally, until beans are crisp-tender, 3 to 4 minutes. Remove from heat and stir in onion, lemon zest and juice, parsley, and feta. Serve chicken alongside.