NightJar, a new pop-up venue opening next door to Nightbird in Hayes Valley from chef Kim Alter and partner/GM Ron Boyd, is debuting this week and will spend its first three months serving a menu inspired by House of Prime Rib.

It's a surprise new project for Alter and the Nightbird team, and as the Chronicle reports, it opens Wednesday in the former flower shop space next door to Nightbird at 334 Gough Street. The first pop-up, dubbed PrimeBird, will feature an $80-per-person prix fixe centered on aged prime rib. It will also include a green garlic goddess salad, truffled Yorkshire pudding, creamed spinach, and a miniaturized (think large fingerling) loaded baked potato.

The main dish at PrimeBird. Photo by Adahlia Cole, via OpenTable

There will also be whipped cheesecake for dessert with strawberry and rhubarb. And, like at HOPR, Martinis and Manhattans will be served, along with a list of sparkling and still wines.

Alter says that House of Prime Rib, which has been in its well-worn digs on Van Ness Avenue serving a limited menu of prime rib and several side dishes since 1949, is one of her favorite restaurants.

In a press release, Alter says, "We’ve been carefully planning for the opening of NightJar, especially with the challenges that the restaurant industry has faced over the past few years and are beyond excited to introduce our PrimeBird pop-up and this space as a beacon of hope for the future."

That future will include to-be-announced guest-chef pop-ups and other special events after the initial run of PrimeBird, and PrimeBird will apparently pop up later during times when there is nothing else booked in the NightJar space.

Alter has simultaneously been in the process of rolling out a new menu at Nightbird — arguably the most underrated fine dining restaurants in town — where the nightly prix fixe starts at $195 per person. A recent spring menu had a dish that is an homage to California seafood, featuring an oyster and uni together in a bowl; a riff on the "Awesome Blossom" fried onion at Outback Steakhouse; and a dish of squab with an allium-laced cauliflower puree and brassicas.

A recent squab dish at Nightbird, via Instagram.

The new Nightbird menu, which debuted Friday, features dishes inspired by visual artists, Alter says.

PrimeBird at NightJar will have reservations available here on OpenTable, though those appear to not be live yet as of today. The small storefront space only has room to accommodate 10 diners at a time, so this could end up being a tough reservation to get if it catches on. The initial run of PrimeBird will go through the summer, and it sounds like it will own be open three days a week, from Tuesday to Thursday. (On weekends, the space will be used as Nightbird's private dining room, dubbed the Nightingale Room.)