Prepare orzo per directions on the box. Drain and set aside.
In the meantime, heat 3 tablespoons olive oil in a large skillet set over medium-high heat.
Add chicken pieces and asparagus; season with salt and pepper and cook for 8 to 10 minutes, stirring frequently, until chicken is cooked and browned on all sides.
Add tomatoes and continue to cook for 2 to 3 minutes or until tomatoes are tender; set aside.
Heat olive oil and melt butter in a separate large pan over medium-high heat. Sprinkle with flour and whisk to combine, whisking and cooking for 1 to 2 minutes.
Whisk in the chicken broth until thoroughly combined. Whisk in the milk, and bring the mixture to a simmer; allow to cook for 1 minute or until thickened.
Remove from heat, add parmesan cheese, and season with salt and pepper; stir until the cheese is melted.
Drain the pasta and add it to the sauce with the chicken, asparagus, and tomato mixture. Toss well to combine. Taste for salt and pepper and adjust if needed.