Instructions

1. Make the pastry dough by placing flour and salt in a large bowl and whisking to sift together. Add the cold butter pieces and toss in the flour to to coat. Rub the butter between your fingers until a crumbly mixture forms. Add the eggs and stir with a fork to combine then work the dough lightly with your hands until it holds together. Turn onto a lightly floured work surface and knead briefly until smooth (without overworking) then shape into a round, flat disk. Wrap the dough in plastic wrap and refrigerate for at least 2 hours and up to 24 hours.
2. Trim off the stems from the spinach bunch and discard. Rinse the leaves well in several changes of cold water and drain. Place the spinach with water clinging in a large skillet or sauté pan with a tight fitting lid. Sprinkle with salt then cover and cook over medium heat for about 8 minutes or until leaves are tender, stirring occasionally and adding a small amount of water if needed to prevent scorching. The spinach will reduce in mass considerably as it cooks. Lift the cooked spinach out of the pan and transfer to an ice water bath for a couple of minutes then drain well (this will preserve its green color). Gather the spinach into a ball with your hands and squeeze well to eliminate all excess moisture, then place of a cutting board and chop finely.
3. Heat the olive oil, 1 tablespoon of the butter, minced shallots, pinch of salt, and 2 tablespoons water in a skillet over medium heat. Sauté the shallots until softened and all water has evaporated without browning,, 2 to 3 minutes. Add the chopped spinach, season lightly with salt and pepper and cook for a few minutes, stirring to coat spinach with the cooking oils. Remove from heat, transfer to a mixing bowl and cool completely. When cool, add the ricotta and chopped marjoram and mix well.
4. Using a rolling pin on a lightly floured work surface, roll the pastry dough into a 15-inch circle. Transfer the sheet of pastry to a buttered tart tin, centering it in the pan, and smoothly line the sides and bottom with dough. Roll the overhanging dough into a border then pinch, cut or mark to create a decorative edge (I roll it toward the center then make diagonal cuts to form beaks). Place tart shell on a baking sheet in the refrigerator until needed.
5. Preheat the oven to 400°F/200°C.
6. Heat the cream in a small saucepan until small bubbles form around the edge of the pan but without boiling. In a medium bowl, beat 2 of the eggs well together with grated cheese then slowly add the warm cream, a little at a time, while whisking continuously. Season the egg mixture with ½ teaspoon salt, freshly ground pepper, and nutmeg if desired.
7. Spread the spinach ricotta mixture evenly over bottom of the tart crust. Sprinkle with a layer of chopped ham then with a layer of chopped fontina cheese. Carefully pour the egg mixture over top. Prepare an egg wash by beating the remaining egg with 1 tablespoon cream then brush the pastry border with the wash.
8. Place the tart in lower half of the hot oven and bake for about 40 minutes until the custard is set and the pastry is deep golden brown. Remove from oven and cool for 10 minutes before cutting into wedges. Serve warm or at room temperature.