Rinse the manila clams under cold water, scrubbing the shells clean. Discard any that do not close when tapped.
Prepare the noodles according to the package directions. Drain and rinse immediately under cold water to stop cooking and cool them down completely. Set aside.
In a pot, combine water, sake, and hondashi powder. Bring to a boil, then add the manila clams. Lower to a simmer and cover the pot. Make sure you do not boil the clams!
Cook and let clams steam for 6 minutes until the clams open. Remove the clams and set aside, discarding any that did not open.
Add the whites of the green onions, black pepper, and lemon juice to the clam dashi stock. Stir to combine and then add ice. Set chilled stock aside.
Remove clam meat from shells if desired, or leave in shells for presentation.
Place the cold noodles in bowls. Pour the chilled clam broth over the noodles. Top with the cooked clams, extra virgin olive oil, additional black pepper to taste, and finally the greens of the green onions, and lemon slices. Serve and enjoy!
