Linguine with Herb Broth and Clams

Melt butter with olive oil in heavy large pot over medium heat. Add onions and cook until soft, stirring often, about 5 minutes. Add garlic and stir 1 minute. Add tomatoes and cook until beginning to soften, stirring often, about 2 minutes. Add white wine and 1 cup water and bring to boil. Reduce heat to low, cover, and simmer 20 minutes to blend flavors. DO AHEAD: Broth can be made 1 day ahead. Cool slightly, then cover and refrigerate.

Bring broth to boil. Add clams, cover, and cook until clams open, 3 to 5 minutes (discard any clams that do not open). Transfer clams to large bowl; tent with foil to keep warm.

Stir basil, parsley, oregano, and crushed red pepper into broth in pot. Add linguine. Boil until pasta is almost tender but still very firm to bite, stirring often and adding water by tablespoonfuls if too dry. Return clams with any accumulated juices to pot. Cover and simmer until clams are heated through and pasta is tender but still firm to bite, about 3 minutes longer. Season to taste with salt and pepper.

Transfer linguine and clam mixture to large shallow platter and serve.