Local SEO is a large phrase for a small, specific fight: getting your restaurant into the three-result box that appears above the ordinary search results on Google, and onto the map beside it.

What Google is weighing

Google describes local ranking as three factors, and they are worth taking literally.

Relevance — how well your listing matches what was searched. A profile that says "Restaurant" competes for less than one that says "South Indian restaurant" and has a menu, attributes and photos backing that up.
Distance — how far you are from the searcher. You cannot change this, and no amount of optimisation moves your building.
Prominence — how well known and well regarded you appear to be, drawn from reviews, mentions elsewhere on the web, and your website's own standing.

Two of those three are things you can work on. Almost everything useful in restaurant local SEO is relevance and prominence.

Relevance: describe yourself precisely

Pick the most specific primary category that is honestly true, then add the secondary ones. Fill in the attributes — outdoor seating, delivery, vegetarian options, wheelchair access. Upload the menu. Add photos of the room and of the dishes, not just the logo.

Every one of those fields is a signal that you match a more specific search, and specific searches are the ones with an intent to visit attached.

Prominence: reviews are the engine

Review count, review recency and review responses all feed prominence. A restaurant with forty recent reviews, all answered, generally outranks one with two hundred reviews from three years ago and no replies.

Ask for reviews in person, at the moment the meal went well. Never buy them, never write them yourself, and never offer a discount for one — Google filters what it detects, and the damage from being caught is permanent in a way a slow month is not.

NAP consistency, which sounds boring and is not

Name, address, phone. These need to be byte-for-byte the same on your Google Business Profile, your website, your delivery listings and anywhere else you appear. "Shop 4" in one place and "Shop No. 4" in another is enough to weaken the association Google is trying to make between all these mentions and one real business.

What your website contributes

Your site is a prominence signal even for searches that never reach it. Give it a page that names the neighbourhood you are in, mark it up with LocalBusiness structured data that matches the address on the page exactly, and make sure the phone number is a real link on mobile.

What not to do

Do not create separate location pages for cities you do not operate in. Do not stuff keywords into your business name on the profile — it violates Google's guidelines and gets listings suspended. Do not create a second listing for the same address hoping to occupy two slots.

Local SEO for restaurants is unglamorous maintenance done consistently. That is genuinely most of it.

Local SEO for Restaurants: How to Rank in the Google Map Pack