Bring a large pot of water to a boil and have ice water ready nearby. Blanch asparagus for 2 minutes, or just until the color turns bright green. Stop the cooking in the ice water and dice.
To make dressing, whisk together shallot and lemon juice in a medium bowl. Slowly drizzle in evoo while whisking. Then whisk in sumac, salt, and pepper to taste.
When ready to serve, toss arugula with asparagus, tomatoes, and dressing. Top with feta and eggs.