This Vietnamese scallion oil recipe for mo hanh makes a Vietnamese dressing that’s as much about the unctuous mouthfeel as the rich, sweet flavours and vibrant colour. In Vietnam, mỡ hành is the vivid green onion dressing spooned over grilled seafood, especially oysters, clams, scallops, and cockles. The richness and sweetness of the spring onion oil provides the perfect balance to plump briny molluscs that taste of the salty sea. It’s also fantastic drizzled over steak and vegetables.
If you’re a seafood lover who has spent an evening in Vietnam perched on a tiny plastic stool on a beach or in a boisterous laneway eatery, slurping oysters and razor clams drizzled with this deliciously-rich sweet Vietnamese spring onion dressing, you know what I’m talking about. If you haven’t, make that a priority. In the meantime, make this Vietnamese scallion oil recipe for mỡ hành.
You’ll love this Vietnamese spring onion oil if you’re fond of tucking into fresh seafood just-cooked on a grill or barbecue, dressed with little else but a squeeze of lemon and a sprinkle of fresh parsley or dill. Spoon the moreish dressing over charred octopus, whole fish or lobster halves and there’s no going back. Serve dishes of the oily green onion dressing on the table as a dipping sauce for prawns and crab legs and guests will be asking for the recipe.
In Hanoi, where we lived on ‘Food Street’, and first sampled mỡ hành; on Halong Bay, where we first learned to make mỡ hành; and at dreamy Dam Lap An, between Hoi An and Hue, one of my favourite places to savour this Vietnamese specialty, the scallion oil is spooned onto oysters with its close companions, crushed roasted peanuts and crunchy fried shallots. I’ll share a recipe for that dish, hàu nướng mỡ hành, very soon.
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Vietnamese Scallion Oil Recipe for Mo Hanh for Seafood Dishes
I vividly recall the first time we tried this addictively-delicious Vietnamese scallion oil at a brightly-lit bia hoi joint in Hanoi that specialised in seafood, as the vivid green dressing was spooned over absolutely everything. We washed the lot down, clinking recycled glasses of Vietnam’s famous ‘fresh beer’ in between bites.
We were with a group of Hanoi locals and long-term Vietnam expats who ran a small tour company, riding around Vietnam’s elegant ancient capital, enchantingly illuminated after dark, in ex-military jeeps and motorbikes. We were testing out an early incarnation of a bia hoi tour, which was essentially a Hanoi pub crawl and it was the best fun.
The next time we tasted the sweet and savoury Vietnamese spring onion oil was on a series of Halong Bay cruise boats, testing out cruises on Halong Bay and Lan Ha Bay for magazine stories. Almost every meal began with a plate of grilled oysters drizzled with scallion oil and sprinkled with pan-roasted peanuts and crunchy fried shallots.
It was on those Halong Bay cruises that we also learnt to make this Vietnamese scallion oil. One of the things to do on a Halong Bay cruise in the evening — after an action-packed day in the sun spent visiting floating fishing villages, clambering around caves, kayaking beneath the karsts, and cycling on Cat Ba Island — is a Vietnamese cooking class.
Compared to the cooking classes in Hanoi that have become some of the most popular things to do in Vietnam’s capital (along with Hanoi street food tours!), the cooking classes on Halong Bay cruises are relaxed affairs, and more demo-style than hands-on. But after busy days out on the water, guests don’t mind one bit that all they’ll have to do is roll up some spring rolls or stir scallions in a pot — with a gin and tonic on hand.
While this Vietnamese scallion oil is mainly spooned over seafood in Vietnam, it’s fantastic drizzled over a great steak as you do with chimichurri in Argentina, or doused onto vegetables. I’ve spotted mentions of how mỡ hành is spooned over corn cobs in Vietnam, but in my experience that condiment includes fish sauce and coconut milk, as it is with this Cambodian street corn, poat dot — which only goes to show how versatile this Vietnamese scallion oil is.
I only have a few tips to making this Vietnamese scallion oil recipe for mỡ hành as it’s a quick and easy condiment to prepare.
Tips to Making this Vietnamese Scallion Oil Recipe for Mỡ Hành
I only have a few tips to making this Vietnamese spring oil recipe for mỡ hành but just a quick note on the key ingredient and my use of scallion and spring onions.
Scallions and Spring Onions
A mỡ hành recipe mostly gets translated to a Vietnamese scallion oil recipe online and I want home cooks to find this when they’re researching the Vietnamese seafood dressing.
However, for our readers from Australia and many other countries, mỡ hành is a Vietnamese spring onion oil recipe, as ‘scallion’ and ‘spring onion’ is used interchangeably in Australia and many other parts of the world, just as it is in Vietnam, where ‘scallion’, ‘spring onion’ and ‘green onion’ were all used to mean the same thing.
When we lived in Vietnam, our Vietnamese friends mostly worked in food and travel. They were chefs, restaurant owners, cooking instructors, and culinary tour guides; many were multilingual, used to adapting their vocabulary depending on who they’re speaking to; and many had lived abroad.
So we’re using scallions and spring onions interchangeably here, too. But are they the same? I’ll cover that subject in part two of this post :)
Step-By-Step Process
This Vietnamese scallion oil recipe for mỡ hành is a cinch to make, taking just ten minutes or so, but here’s a quick rundown of the process.
Prep the Scallions/Spring Onions
To a stainless steel mixing bowl, add the finely-sliced green parts of the scallions — or spring onions or green onions, depending on where you are and what you call them.
Heat the Vegetable Oil
In a small pan over medium-high, heat the vegetable oil just until it begins to smoke.
Pour the Oil on the Scallions/Spring Onions
Immediately pour the oil into the stainless steel bowl and stir until the sliced scallions are fully coated and start to soften.
Add Sugar and Fish Sauce
To the same bowl, add the half teaspoon each of caster sugar and fish sauce (or, if you prefer, salt, to taste) and stir until well-combined and the oily dressing takes on a smoky appearance and unctuous texture.
Adjust to Suit Your Taste
Taste and adjust the seasoning to suit your palate, then set the bowl aside to allow the scallion oil to reach room temperature.
Serve Immediately or Store
If you’re not serving the scallion oil straight away, transfer it to a screw-top jar and refrigerate it, but note that it won’t be as vividly coloured the next day.
Before storing, leave the scallion oil on the kitchen counter to return to room temperature, and give it a thorough stir before transferring it to a serving a dish or spooning it over seafood.
Vietnamese Scallion Oil Recipe for Mỡ Hành
Equipment
Ingredients
- 6 scallions - also called spring onions or green onions, green parts only, washed and dried, and thinly sliced
- ½ cup vegetable oil - or another neutral oil such as canola
- ½ tsp caster sugar - or super-fine white sugar, optional
- ½ tsp fish sauce - or, if you prefer, salt to your taste
Instructions
- To a stainless steel mixing bowl, add the finely-sliced green parts of the scallions — or spring onions or green onions, depending on where you are and what you call them.
- In a small pan over medium-high, heat the vegetable oil just until it begins to smoke then immediately pour the oil into the stainless steel bowl and stir until the sliced scallions are fully coated and start to soften.
- To the same bowl, add the half teaspoon each of caster sugar and fish sauce (or, if you prefer, salt, to taste) and stir until well-combined and the oily dressing takes on a smoky appearance and unctuous texture.
- Taste and adjust the seasoning to suit your palate, then set the bowl aside to allow the scallion oil to reach room temperature.
- If you’re not serving the scallion oil straight away, transfer it to a screw-top jar and refrigerate it, but note that it won’t be as vividly coloured the next day.
- Before storing, leave the scallion oil on the kitchen counter to return to room temperature, and give it a thorough stir before transferring it to a serving a dish or spooning it over seafood.
Please do let us know if you make this Vietnamese scallion oil recipe for mỡ hành as we’d love to know how it turns out for you and how you like to use this Vietnamese spring onion oil.
