Bring 2 large pots of water to boil. Add a big pinch of salt in each.To one pot, add asparagus and blanch, about 2 to 3 minutes, depending on the thickness of your asparagus. Place blanched asparagus in a bowl of ice water to stop the cooking and keep them green.
To the second pot, add the orzo. Cook per package instructions. When tender, drain and place in a large bowl. Add blanched asparagus and tomato halves.
Mix olive oil, lemon zest, lemon juice, garlic, salt and pepper in a small bowl. Stir into orzo and vegetables. Stir in parsley and grated Parmigiano Reggiano.
This can be served warm, room temperature or cold..