In a large pot, bring 4 quarts of water plus 1 tbsp of salt to a boil.

Cook the pasta according to package directions and drain reserving 1 cup of the pasta water.

While pasta cooks, heat 2 tbsp of the olive oil in a large saute pan over medium heat.

Place the shrimp, garlic and 1/4 tsp salt in a saute pan and cook for 3 minutes, stirring halfway through (make sure not to overcook the shrimp).

Remove the shrimp to a plate and add the clam juice into the same saute pan.

Bring the clam juice to a boil for 5 minutes or until the liquid is reduced by half.

Whisk the butter, lemon juice and parsley into the saute pan and add the pasta, shrimp and as much of the reserved pasta water as necessary to make a sauce to coat the pasta.

Top with additional parsley or grated cheese if desired.