Since I don't live in LA I am not in a position to recommend a local restaurant or more to ID what you need.
But I'll toss out a few more comments.
Good Cantonese does not necessarily equate to top seafood restaurants. Although common sense dictates that such places (like the Elites and Sea Harbors) are certainly the places to go for fresh out of the tank seafood.
But Cantonese food can be enjoyed from the "streets" level all the way up high end seafood restaurants. Then there's the in between's, the places that do BBQ and/or stir fry, where some of the seafood restaurant dishes can also be found and ordered. If it is within reason, 99% of all Cantonese restaurants (that do jack of all trade types) can reproduce the same dish, whether it be black bean sauce clams, dry fried beef chow fun, or what not.
A few years ago I've been reading a book published by a Hong Kong media personality about the flavors of Hong Kong. Some (not all) of the dishes may be found or recreated to some extent abroad. Here are some examples you may want to investigate and see if there are establishments in Southern Cal that do them
- Hakka Cantonese style salt baked chicken (many restaurants in NorCal steam it in brine or salt water, it's not the same)
- roast squab
- steamed fish (most Norcal Cantonese restaurant serve the typical black bass, but if they have something a bit more exotic, perhaps rock cod or something deep sea, give it a try, but bring a ton of friends with you)
- crab and lobster dishes (the preps are endless....salt baked crab, salted egg yolk crab, Indonesian style crab, Typhoon shelter garlic black bean sauce chili sauce crab, Under Bridge spicy garlic crab, Chiu Chow style cold crab, cheese baked lobster, supreme broth lobster, ginger scallion lobster (or crab) etc etcr etc
- crab with sticky rice in steamed bamboo container (whoops forgot, LA health dept banned bamboo steamers)
-fried oysters (puffy exterior like dim sum taro puff), black bean sauce oysters
-black bean sauce stir fried clams (also try basil stir fried clams for a Hakka style slant)
-sweet and sour pork (inquire ahead of time if the chef uses ketchup or haw flakes for the sweet and sour sauce)
-salted fish steamed pork patty (with or without dried squid)
-lamb brisket clay pot (great during cold winter nights)
-scrambled eggs with shrimp
-a tofu dish called Lo Siu Ping On (it's basically tofu steamed with egg whites, so soft that toothless kids and adults could eat them), basically the Cantonese waiter has to know what this is and tell the competent chef
-in Hong Kong there are dishes based on braised pomelo skin (stewed with vegetables). I have not seen that in NorCal yet.
-slow cooked soups of the day (varies according to the restaurant). A great starter to any meal
-winter melon soup (in winter melon as the base and shell). Some places require advanced order. Perhaps some Taiwanese restaurants would offer something like this too.
- There's more to Cantonese BBQ than the tried and true BBQ pork, roast pork, roast duck, soy sauce chicken. Inquire at the restaurant what else they might have from their deli butcher. The poached or steamed chickens, like Princess Chicken (actually a more complex cooking process from start to finish) is great.
- claypot rice
-beef brisket clay pot (if the restaurant is able to do an authentic Hong Kong style curry brisket clay pot, prepped in advance, it's a keeper)
- another nice claypot dish is salted fish, chicken, and tofu. Other family members like salted fish, chicken and eggplant claypot, or sacha beef and bean thread noodle claypot (with onions). Way too many possibilities here.