- 1 cup grated Parmesan (about 4 ounces), plus one 3-inch piece Parmesan rind
- kosher salt and black pepper
- 2 tablespoons olive oil
- 1 medium onion, chopped
- 6 cups low-sodium vegetable broth
- 4 sprigs fresh thyme, plus leaves for serving
- 2 10-ounce bags frozen peas (about 4 cups)
- 1/2 cup low-fat plain yogurt
- Heat oven to 375° F. Line a baking sheet with parchment.
- Spoon the Parmesan onto the baking sheet in 8 mounds (about 2 tablespoons each), spaced 1 inch apart. Flatten the mounds gently with your fingers, then season with ½ teaspoon pepper. Bake, rotating the baking sheet halfway through, until golden and bubbly, 10 to 12 minutes. Let cool for 5 minutes, then remove from the parchment.
- Meanwhile, heat the oil in a large pot over medium-high heat. Add the onion and ¼ teaspoon each salt and pepper and cook, stirring often, until beginning to soften, 5 to 7 minutes.
- Add the broth, thyme, and Parmesan rind and bring to a boil. Reduce heat and simmer, stirring occasionally, until the liquid is slightly reduced and the Parmesan rind is very soft, 10 to 15 minutes; add the peas during the last 3 minutes of cooking. Remove the thyme sprigs and Parmesan rind.
- In batches, puree the mixture in a blender until smooth. Serve drizzled with the yogurt, sprinkled with the thyme leaves, and topped with the Parmesan crisps.