In a large baking dish, add all the ingredients, stirring to combine.
16 ounces spaghetti noodles, 16 ounces marinara sauce, 4 cups boiling water, 1 cup baby tomatoes, 3/4 cup artichoke hearts, 3/4 cup kalamata olives, 1/2 cup green olives, 1 teaspoon dried oregano or Italian seasoning, 1 teaspoon salt, 1 teaspoon black pepper, 4 cloves garlic, 1/2 red onion, 2 Tablespoons olive oil