Squid, Potato and Olive Stew

Ingredients

• 1 pound cleaned squid, both tubes and tentacles
• 3 tablespoons olive oil, divided
• 2 medium onions, peeled and diced
• 1/4 teaspoon red pepper flakes
• 3/4 teaspoon dried oregano
• 6 cloves garlic, peeled and sliced
• 1/2 cup dry red wine
• 1/2 cup clam juice
• 1 can (32 ounces) peeled San Marzano tomatoes
• 1 1/4 pound Idaho/russet potatoes (about 2 medium)
• 1/2 cup mixed pitted olives, rinsed, drained, dried and halved
• 6 ounces baby spinach