Prep Time: 5 mins Cook Time: 25 mins
6 medium garlic cloves, divided
4 cups chopped scallions, green parts only (from 4 bunches)
3/4 cup heavy cream
1/4 teaspoon kosher salt
12 ounces uncooked bronze-cut garganelli pasta
1/4 cup cold unsalted butter (2 ounces), cut into 1/2-inch pieces, divided
1 1/2 cups sweet peas (6 ounces)
2 ounces thinly sliced speck (about 8 slices), torn into 2-inch strips
1 ounce Parmigiano-Reggiano cheese, grated with a Microplane grater (about 2/3 cup)
1/2 cup coarsely chopped fresh mint
1 teaspoon lemon zest plus 1 teaspoon fresh lemon juice (from 1 lemon)
Smash 3 garlic cloves. Place scallions, cream, and smashed garlic in a small saucepan. Finely chop remaining 3 garlic cloves to equal 1 tablespoon; set aside.
Bring scallion mixture to a boil over medium-low. Reduce heat to low; simmer, stirring occasionally, until scallions are crisp-tender and garlic is softened, about 10 minutes. Pour mixture into a blender. Secure lid; remove center piece to allow steam to escape. Place a clean towel over opening. Process until smooth, about 40 seconds. Stir in salt; set aside.
Cook pasta in a pot of boiling water until very al dente, 3 minutes less than package directions.
While pasta cooks, melt 2 tablespoons butter in a large skillet over medium. Add reserved 1 tablespoon chopped garlic; cook, stirring often, until softened and fragrant, about 1 minute and 30 seconds.
Using a slotted spoon, transfer pasta to skillet, reserving pasta water. Add scallion-cream mixture and peas to skillet; increase heat to medium-high. Add 1/4 cup reserved pasta water; cook, stirring and shaking skillet constantly, until pasta is tender and sauce is loose and creamy, about 2 minutes. Remove from heat; add speck, cheese, mint, lemon zest and juice, remaining 2 tablespoons butter, and 1/4 cup pasta water, stirring until combined.