This Manhattan-style chowder base is chock full of tomatoes, summer vegetables and herbs — keep it on hand for fast, fresh fish or seafood chowder. Freeze in quarts and then add any combination of oysters, shrimp, crab, clams, scallops or fish at serving time. We topped ours with crispy fried oysters.
In a heavy pot, cook bacon, sweet potato and onion over medium heat for about 3 minutes to render some drippings.
Add remaining fresh vegetables and sauté until al dente, about 5 minutes.
Stir in remaining ingredients except butter and seafood and bring to a simmer. Cook 5–7 minutes until vegetables are tender.
Season with salt and pepper as needed.
Remove rosemary stems and bay leaves.
Cool and freeze or enjoy now.
At chowder time: Heat base to a low simmer. Stir in 2 tablespoons butter per quart. Add seafood and cook just until done, making sure not to overcook. Most will be done in 3–5 minutes. Or simply “garnish” warm chowder with cooked seafood. Add about 1 pound of fish or seafood per quart or as desired.