- Line a 12 x 17-inch (30 x 43 cm) baking sheet with parchment paper.
- On a floured surface, roll the dough out to a 12 x 17-inch (30 x 43 cm) rectangle. Transfer to the baking sheet. Fold the edges of the dough inward, making a ½-inch (1 cm) border all around. Refrigerate for 30 minutes.
- In a skillet, brown the onions in the oil. Season with salt and pepper. Let cool.
- In a bowl, combine the onions, ham, sour cream and mustard. Refrigerate.
- In a pot of salted boiling water, blanch the asparagus for 1 to 2 minutes or until tender. Transfer the asparagus to a bowl of ice water. Drain and set aside.
- With the rack in the middle position, preheat the oven to 400°F (200°C).
- Spread the ham mixture evenly over the dough. Place the baking sheet with one of the long sides parallel to the edge of the work surface.
- Mentally divide the pie into six 5-inch (12 cm) squares. Working from left to right, lay about 8 green asparagus pieces vertically in the first square. In the next square, lay about 8 white asparagus pieces horizontally. Repeat with the remaining squares, alternating colours and directions to create a quilt effect.
- Bake for 25 minutes. Remove from the oven. Crack an egg at the centre of each square. Bake for 10 more minutes or until the eggs are cooked. Cut into 6 squares and serve.