Combine 2 tablespoons olive oil, the garlic and thyme in a small bowl; brush on the steak, then season with salt and pepper. Toss the asparagus with the remaining 1 tablespoon olive oil and season with salt and pepper.
Bring a pot of salted water to a boil. Add the orzo and cook as the label directs; drain and return to the pot. Add the half-and-half and cook over medium heat, stirring, until slightly thickened, about 1 minute. Remove from the heat; stir in the gruyere. Season with salt and pepper.
Meanwhile, heat a grill pan over medium heat and brush with olive oil. Grill the steak 3 to 4 minutes per side for medium rare; transfer to a plate. Wipe off the grill pan. Grill the asparagus, turning occasionally, until marked, 4 minutes; drizzle with the lemon juice. Slice the steak and serve with the asparagus and orzo. Top the orzo with the scallions.