Annette Yang and Brian Leitner of Nettie's Crab Shack in Cow Hollow are cracking tradition into shards with their new weekly venture.

During the winter months, the fish house known for its standout à la carte menu featuring whole Dungeness crab and steamed clams was shuttered on Mondays.

Now, every Monday between 5 and 8 p.m., the pair offers a set menu of three inspired courses menu for a paltry $30. Only 30 people are admitted, because--in a remarkably intimate move--Yang and Leitner run the show by themselves (with the exception of a lone busser-runner the night we attended).

Leitner plans the menu the day before, based on both what fish and produce are choicest and what he feels like cooking. When we dined last Monday for the new format's second outing, Leitner grilled chicories, taming their intoxicating bitterness with anchovy vinaigrette and bits of hard-boiled egg. He then pan-roasted Alaskan halibut, surrounding it with a moat chockablock with green-garlic broth, house-made sausage, Manila clams and green chickpeas. To finish, there were two desserts--a deeply zippy ginger cake with blood orange, and a tangerine upside-down cake.

Note: The smart, reasonably priced wine list full of fish-friendly choices like Chenin Blanc and Riesling is worth a splurge--especially when the meal itself is such a steal.

Nettie's Crab Shack, 2032 Union St. (at Buchanan St.); 415-409-0300 or nettiescrabshack.com