Add the ground beef into a bowl and then add the chives, dill, parsley, and garlic powder. Season generously with salt and freshly ground black pepper and mix thoroughly to evenly combine.
Form 10 even-sized meatballs from the mixture and place them onto a baking tray lined with kitchen paper.
Drizzle over a tablespoon of olive oil and bake in the oven for 13-15 minutes until cooked through.
In the meantime, trim the green beans and cook in a saucepan of rapidly boiling water for 4 minutes. Drain and plunge into a bowl of cold water to cool completely. Drain again.
Toss the green beans, petit pois, baby spinach, and arugula in a bowl and another tablespoon of olive oil. Season with salt.
Serve the meatballs over the greens and crumble the feta cheese over them.
Finish with the pistachios and a squeeze of fresh lemon. Toss on any remaining herbs.