1. Heat oil in a large nonstick skillet over medium-low heat. Add onion and salt and cook, stirring often, until soft and just beginning to brown, 4 to 6 minutes. Add rice and garlic and cook until the garlic is fragrant, 30 seconds to 1 minute. Add broth and bring to a boil; cover, reduce heat to a simmer and cook for 5 minutes.
2. Remove cover and spread asparagus and bell pepper on top of the simmering rice—do not stir into the rice mixture. Replace cover and continue simmering, adjusting the heat if necessary, until the liquid is almost absorbed and the asparagus is bright green but still crisp, about 5 minutes.
3. Add peas and cream cheese; stir until the mixture is creamy and the cheese is incorporated. Return to a simmer and continue cooking until the liquid has evaporated and the asparagus is tender, about 5 minutes more. Stir in 1/2 cup Asiago (or Parmesan). Serve topped with chives (or scallions) and additional grated cheese.