In a small saucepan over medium heat, reduce the vin santo to 1/3 cup, about 10 minutes.
In a small bowl, combine the reduced vin santo, lemon juice, mustard, salt, and pepper. Whisk to combine, making sure the mustard is fully dissolved. While whisking slowly drizzle in the olive oil.
Bring a large pot of salted water to a boil over high heat. Add the asparagus. Cook until just tender, about 3 minutes. Transfer the asparagus to a bowl filled with ice water and let cool, about 3 minutes. Remove from water and pat dry with paper towels.
Place the lettuce leaves on a serving platter and top with the asparagus, then the slices of hard boiled egg and chopped almonds. Drizzle the entire platter with the vinaigrette. Serve immediately.