Risotto with Clams

Name: Risotto with Clams
Ingredients: 1 tablespoon extra-virgin olive oil; 4 ounces pancetta, diced; 2 shallots, chopped; 2 cloves garlic, chopped; 1/4 teaspoon salt; 1 cup Arborio rice; 1 cup plus 1/2 cup prosecco; 2 1/4 cups jarred clam juice or seafood broth; 1 pound New Zealand clams, scrubbed; 1/2 cup freshly grated Parmesan; 2 tablespoons butter, room temperature; 12 littleneck clams, shucked and chopped, juice strained; 1/4 cup Italian parsley leaves, chopped; 2 teaspoons grated lemon zest (2 lemons)