In a large pot, bring water to a boil. Add asparagus and salt. Cook for 3 to 4 minutes, or until stalks become bright green. Remove from boiling water and transfer to a bowl of ice water. Drain and set aside.
Heat oil in a large skillet over medium-high heat. Add mushrooms and cook stirring occasionally, until browned and liquid has evaporated, about 6 minutes.
Meanwhile, bring a large pot of salted water to a boil. Cook orzo for al dente texture, according to package instructions. Drain, transfer to a large bowl and set aside to cool.
To make the vinaigrette, combine vinegar, mustard, zest, juice, thyme and salt and pepper in a small bowl. Using a whisk, slowly pour in olive oil while stirring constantly. Adjust seasoning as needed.
Add the vinaigrette to the orzo and toss well. Divide evenly into bowls and top with mushrooms, asparagus, scallions and almonds.
Sprinkle with Parmigiano-Reggiano and dill (optional).