Saute red onion & radicchio in olive oil, season with salt and pepper and set aside. Grill the calamari steaks for two minutes on each side, or longer to taste. Season with salt and pepper on both sides and allow to rest in a warm oven. To serve, divide the sauteéd vegetables equally on four plates, place the calamari steaks on top, pour pesto sauce and garnish with lemon or lime wedges.