Step 1

Place one 10-oz. package frozen peas (about 2 cups) in a fine-mesh sieve and place in a large pot of boiling salted water; cook until peas are tender, about 4 minutes. Add 1 cup (lightly packed) basil leaves and cook until just wilted, about 10 seconds. Lift sieve from water to drain peas and basil and transfer to a blender. (Alternatively, you can skip the sieve and use a spider or slotted spoon to fish out the peas and basil.) Reduce heat to medium-low and keep cooking liquid warm.

Step 2

Add ½ cup finely grated Parmesan, 2 Tbsp. unsalted butter, cut into 4 pieces, and ½ cup cooking liquid to blender and blend, gradually increasing speed to high and adding up to ¼ cup additional cooking liquid as needed, until you have a mostly smooth, fairly loose sauce; season with kosher salt.

Step 3

Return cooking liquid to a boil over medium-high heat. Add 16–20 oz. fresh (or frozen) ravioli and cook, stirring gently to unstick, until tender, about 5 minutes or according to package directions. Drain carefully; reserve pot.

Step 4

Meanwhile, melt remaining 2 Tbsp. unsalted butter in a medium skillet over medium-low heat. Add ¼ cup coarsely chopped raw pistachios or walnuts and cook, stirring often, until butter begins to smell toasty and turn brown, about 5 minutes. Transfer to a small bowl. Add 1 tsp. Aleppo-style pepper, finely grate in zest of ½ lemon, and season lightly with salt; mix well. Slice lemon into wedges.

Step 5

Return cooked ravioli to pot, pour pea sauce over, and stir gently to coat. Using a large spoon, transfer ravioli to plates. Top with more Parmesan and torn basil, then spoon buttered nuts over. Serve with lemon wedges for squeezing over.