Jamie Oliver’s 5 Ingredients Spinach Pie is a straightforward, flavorful pie made with spinach, feta cheese, eggs, puff pastry, and a hint of seasoning. The spinach is combined with creamy feta to create a rich filling, while the puff pastry adds a light, flaky crust. This pie is simple to make and packed with nutritious ingredients, making it a great vegetarian option for any meal.