Cut calamari tubes into 1/4-inch-thick rings. Melt butter in a large skillet over medium-high heat. Add garlic and onion; sauté 3 minutes or until tender and lightly browned.
Add calamari rings and tentacles, broth, and next 5 ingredients. Bring to a boil; reduce heat, and simmer, uncovered, 30 minutes. Add spinach, olives, and pine nuts; simmer 8 minutes or until spinach wilts.