Heat a large drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add poblano, sliced onion, salt, and pepper. Cook, stirring occasionally, until browned and tender, 6-7 minutes. Transfer to a plate. Add a large drizzle of oil and shrimp to pan. Cook until shrimp are pink and cooked through, 3-4 minutes. Stir in remaining lime zest and juice from remaining lime wedges. Season with salt and pepper.