This frittata-like dish is based on a recipe from “At Elizabeth David’s Table” by Elizabeth David. She calls the preparation a “tian,” the French Provençal term that refers to a shallow round earthenware vessel, as well as the dishes baked in it. In our version, we cook the potatoes and wilt the spinach in a skillet on the stovetop but combine the ingredients in a deep-dish pie plate and bake them in the oven. Serve the eggs warm or even at room temperature, with a simple leafy salad to round out the meal. If not serving immediately, hold off on adding the basil garnish—the heat of the eggs will cause it to darken.