In a large mixing bowl, combine ground chicken, basil, dill, oregano, salt, garlic powder, lemon zest, egg, and panko breadcrumbs. Mix until just combined—don't overwork the meat.
Shape the mixture into meatballs, about 1.5 inches in diameter. Heat the olive oil in a large skillet over medium-high heat. Once hot, add the meatballs and cook for about 8 minutes on each side, until golden brown and cooked through. Cover with a lid for the last 5 minutes to ensure they stay moist.
In a small bowl, mix the yogurt, lemon juice, and ranch seasoning (or herbs). Taste and adjust seasoning if needed.
Prepare the couscous according to package instructions. Meanwhile, steam or boil the peas until tender.
Plate the meatballs over a bed of couscous and peas, drizzling everything with the creamy lemon yogurt sauce. Garnish with extra dill or basil if desired.