Savory japanese savory pancake（日本のしょっぱいパンケーキ）、またはCabbage pancake（キャベツで出来たパンケーキ）と説明すれば想像しやすいと思います。
また、日本のピザみたいもの（Japanese pizza-like dish）と説明する人もいます。
ちなみに、同じソース系のたこ焼きは英語で「octopus balls」といいます。また、日本の「ソース」は、Japanese sweet and savory sauce similar to Worcestershire sauce（ウスターソースと近い日本の甘しょっぱいソース）と説明してあげると見た目も味も想像しやすいと思います。
英語でお好み焼きを説明するときは、一般的に「① Japanese pizza」と言います。
一番近い例えかもしれないですね。
私だったら以下のように説明します：
Okonomiyaki is basically a Japanese pizza.
You cook it on a cast-iron pan.
There's no cheese; but mayonnaise and teriyaki sauce is used instead.
Sometimes, if you're lucky (!), they'll put octopus in it!
ジュリアン
o-konomi-yaki is a Japanese savory pancake containing a variety of ingredients. The name is derived from the word okonomi, meaning "how you like" or "what you like", and yaki meaning "grill". The ingredients vary but may include: green onion, meat (generally thin pork belly, often mistaken for bacon), octopus, squid, shrimp, vegetables, konjac, mochi or cheese.
"What is that you're eating?"
"Well, some people,call it Japanese pizza, but really its more like an omelette with vegetable topping."
o-konomi-yaki is a Japanese savory pancake containing a variety of ingredients. The name is derived from the word okonomi, meaning "how you like" or "what you like", and yaki meaning "grill". The ingredients vary but may include: green onion, meat (generally thin pork belly, often mistaken for bacon), octopus, squid, shrimp, vegetables, konjac, mochi or cheese.
お好み焼きは色んな素材の含まれた日本のパンケーキです。お好みという名前は、自分の好きなように、自分の好きなもの、を表し、yakiはgrillを表します。素材は色々あるが、一般的に緑ネギ、薄切り豚肉（ベーコンと間違われがち）、タコ、イカ、エビ、野菜、こんにゃく、もち、チーズなどが含まれることが多い。
"What is that you're eating?"
何食べてるの？
"Well, some people,call it Japanese pizza, but really its more like an omelette with vegetable topping."
ジャパニーズピザと呼ばれているものさ、実際、野菜をトッピングしたオムレツに近いものだけどね。
"What is that you're eating?"
"Well, spme p[eople,call it Japanese pizza, but really its more like an omelette with vegetable topping."
okonomi' means 'your choice' and 'yaki' means 'to grill'
You need to explain it in several sentences. Here's an example below.
"Okonomiyaki" is a savoury Japanese pancake. The name translates to 'okonomi': your choice, and 'yaki': grill. It means you can add whatever you like to the basic recipe, such as meat, seafood, vegetables, kimchi, cheese, or any combination. The base recipe is flour, shredded cabbage and eggs mixed in a bowl, with your choice of toppings mixed in after. It's grilled on a flat surface and can be topped with special okonomiyaki sauce, bonito flakes and nori flakes.
お好み焼きは数行で説明する必要があります。
以下が例文です。
"Okonomiyaki" is a savoury Japanese pancake. The name translates to 'okonomi': your choice, and 'yaki': grill.
お好み焼きは、おいしい日本のパンケーキです。”お好み”はyour choice、”焼き”はgrillに翻訳できます。
It means you can add whatever you like to the basic recipe, such as meat, seafood, vegetables, kimchi, cheese, or any combination.
基本のレシピに、肉、シーフード、野菜、キムチ、チーズ等の好きなものを何でも入れることが出来ます。
The base recipe is flour, shredded cabbage and eggs mixed in a bowl, with your choice of toppings mixed in after.
基本のレシピは、小麦粉、刻んだキャベツ、卵をボールで混ぜ、その語お好みのトッピングを入れて混ぜます。
It's grilled on a flat surface and can be topped with special okonomiyaki sauce, bonito flakes and nori flakes.
お好み焼きは、平らな鉄板で焼き、上に特別なお好み焼きソース、かつお節、青のりをかけることもできます。
There seems to be quite a few different ways to describe "okonomiyaki" and above are the most common ways to explain to someone, what it is.
If you know the names of the ingredients, in English, that is used to make it, it would be easier to explain, if someone asks.
Savory- meaning the opposite of sweet!
In Europe nearly all pancakes, apart from French crepes, are sweet!
Its useful to mention that they're savory as most 'westerners' will think pancakes and presume they are sweet!
Like some of the other contributors you can also mention the ingredients and how its cooked etc.
Hope this helps! ^ ^
Hi, good question! Lots of students ask this!
Okonomiyaki is referred to as 'Japanese pizza' in English.
Sometimes you might have to describe it more if someone has not heard this phrase.
You can call it a Japanese savoury pancake. It comes with many different toppings, just like a pizza, but doesn't always use cheese.
Since this is unique to Japan, it is not always easily understood at first, so comparing it to a pizza or pancake makes it easier for a foreigner to understand.
I hope this helps, good luck!
Okonomiyaki is a Japanese cabbage pancake.
Source of the word:
okonomi - how you like/what you like
yaki - grill
______________________________________________________
Example
A: What is an okonomiyaki?
B: It is a Japanese cabbage pancake.
Okonomiyaki is a Japanese cabbage pancake.（お好み焼きは日本のキャベツでできたパンケーキです）
語源:
okonomi - how you like/what you like（お好み）
yaki - grill（焼き）
______________________________________________________
例
A: What is an okonomiyaki?（お好み焼きとは何ですか？）
B: It is a Japanese cabbage pancake.（日本のキャベツでできたパンケーキです）
Okonomiyaki is a Japanese savory pancake, also often called "Japanese pizza". The toppings vary depending on what you like, as you can add your own toppings.
Okonomiyaki is a Japanese savory pancake, also often called "Japanese pizza". The toppings vary depending on what you like, as you can add your own toppings.
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【訳】
お好み焼きは日本の塩味のパンケーキです。日本のピザともよく呼ばれます。トッピングは好みに合わせて変えられます。
日本 
アメリカ合衆国 
イギリス 
カナダ 
南アフリカ 
