Add the oil to a large, deep skillet or roomy pot (one that comes with a lid) over medium heat. Add the shallots and cook for 2 minutes, stirring often, or until the shallots are clear. Add the garlic and mushrooms, along with a generous pinch of salt. Cook, stirring often, until the mushrooms are tender and reduced in size and have released their juices (about 5-7 minutes).
Add the barley to the skillet and stir everything well. Add the white wine. Cook, stirring every now and then, until the wine has been absorbed (3-5 minutes). Add 2 cups of broth to the skillet. Bring the mixture to a simmer, then reduce the heat to low and cover the skillet. Allow the barley to simmer for 20 minutes.
Stir the barley, then add the remaining cup vegetable broth. Cover the pot and cook for another five minutes. Uncover and fold in the asparagus. Cover and cook for 5 more minutes.
Taste the risotto; the asparagus should be tender and the barley should be toothsome but tender, too. If the meal needs a little more time (this may be true if your asparagus stalks are thick), stir in an extra splash of broth before covering the skillet again and giving it an extra five minutes. When the dish is ready, stir in the nutritional yeast and lemon juice, along with salt and pepper to taste.
Serve, topped with walnut herb parm
if you like!