Stir in tomatoes, clam juice, water and 1/2 teaspoon salt. Bring to a gentle simmer and cook, stirring occasionally, until sauce thickens slightly, 18 to 20 minutes.
Meanwhile, open the cans of clams, drain juice into 2-quart measuring cup. Set clams aside. Add bottle of clam juice to measuring cup, then add amount of chicken stock necessary to make 5-6 cups ...
Other regional variations have also popped up, however, like the tomato-based rendition from Manhattan or the often thinner concoctions from the Pacific Northwest. No matter how it's served up, clam ...