A winner from Michael Symon!

2 dozen Cherrystone clams, (scrubbed, rinsed)
1 cup white wine
1/2 cup olive oil
4 ounces pancetta (minced)
1 cup celery (minced)
3/4 cup shallots (peeled, minced)
4 cloves garlic (peeled, thinly sliced)
pinch of red chili flakes
1/2 cup fresh parsley (chiffonade, plus extra to serve)
1 pound linguine
1 dozen Littleneck clams
1/4 cup white wine

For the Clam Sauce: Preheat a large Dutch oven over high heat. Add Cherrystone clams and white wine. Cover tightly with a lid and steam clams for 5 minutes. After 5 minutes, using a pair of tongs, remove clams that have opened and transfer to a bowl. If some clams have not opened, return lid to cover and check for opened clams every 30-45 seconds. Once all the clams have opened and have been transferred to bowl, remove from Dutch oven from heat and set aside.
Over a large bowl, place a fine mesh strainer. Line the strainer with a layer of cheesecloth and top with 3 coffee filters. Slowly pour the remaining cooking liquid over the filters and allow to strain naturally. Repeat the straining process with fresh coffee filters 2-3 more times, ensuring that there is no grit or sand remaining. Remaining liquid should yield about 2 cups, if it is short, add a splash of white wine or water. Set aside.
When the clams are cool enough to handle, remove from shells and discard shells. Slice off the abductor muscles and discard. Cut clams in half and clean out the dark digestive tract. Roughly chop the clams and set aside.
Return cleaned Dutch oven to over medium heat. Add 1/2 cup olive oil and pancetta. Cook, stirring occasionally, until the pancetta is crispy, about 10-12 minutes. Add celery, shallots, and garlic and sweat until mixture has softened and is fragrant, about 10-12 minutes. Stir in reserved clam broth and chili flakes and bring to a simmer. Remove from heat and stir in parsley and reserved chopped clams. Keep sauce warm or chill and transfer to a refrigerator up to a day in advance.
For the Linguine: Bring a large pot of water to a boil. Add pasta and cook for 1 minute less than package directions.
While the pasta cooks, preheat a large saute pan over high heat. Add Littleneck clams and white wine. Cover tightly and steam, checking to see if any have opened after 2 minutes, and transferring opened clams to a bowl. Continue to steam clams until all have opened. Set aside.
To Serve: Add linguini to prepared clam sauce and stir in additional fresh parsley, tossing to coat. Transfer pasta to a platter and scatter the Littleneck clams around the edges. Serve.
Tip: This recipe works well with either all Cherrystone or Littleneck clams if your local fishmonger does not carry both!