How to Make It
Preheat the broiler to high. Line a baking sheet with foil and coat with cooking spray. Place the mushroom caps, gill sides up, on prepared pan. Broil until some liquid pools in the caps, about 5 minutes. Drain the liquid, turn the caps over, and continue to broil until tender, 3 to 5 minutes longer. Set aside.
Place the asparagus and 1/4 cup water in a small skillet over medium-high. Bring to a boil; cover and cook until the asparagus is almost tender, about 1 minute. Drain the liquid in the pan and add 1 1/2 teaspoons of the oil; cook, stirring occasionally, until the asparagus is tender and lightly browned, about 2 minutes. Transfer to a plate.
Add the remaining 1 1/2 teaspoons oil to the skillet over medium-high. Add the tomatoes, and cook until bursting, about 3 minutes. Add the farro, beans, salt, and pepper, stirring to combine. Cook, stirring occasionally, until heated through, about 2 minutes. Divide the mixture between the mushroom caps, sprinkle with the parsley, and serve with the asparagus.