Go Back
–+ servings

Blooming Onion

Print Recipe Pin Recipe
5 from 1 vote
Prep Time: 20 minutes
Cook Time: 10 minutes
Total Time: 30 minutes
Calories: 600kcal
Servings: 2 People
Metric - Imperial

Ingredients

Onion & Oil

  • 2 Brown (Yellow) Onions Large
  • Vegetable, Canola or Sunflower Oil For Frying

Flour Mixture

  • 150 g Plain Flour All Purpose
  • 4 g Cornflour Cornstarch
  • 4 g Ground Cumin
  • 4 g Smoked Paprika
  • Salt & Pepper To Taste

Egg Wash

  • 1 Egg
  • 250 ml Full Fat Milk

Mayonnaise

  • 1 Egg You Can Use Pasteurised If Needed
  • 180 ml Neutral Oil
  • 7.5 ml White Vinegar or Lemon Juice
  • 5 g Dijon Mustard
  • Salt & Pepper To Taste

Tangy (Outback Style) Mayonnaise

  • Mayonnaise Above
  • 15 g Tomato Ketchup
  • 15 g Horseradish
  • 15 ml Worcestershire Sauce
  • 4 g Smoked Paprika
  • 4 g Garlic Powder
  • 2 g Red Chilli Powder Optional
  • Salt & Pepper To Taste

Method

Mayonnaise

  • Place all of the mayonnaise ingredients into a tall jar or container. Blend with an immersion blender until thick and creamy. Transfer to a bowl.
  • Add the tangy (Outback-style) ingredients, mix to combine, and place in the fridge until ready to serve.

Blooming Onion

  • Preheat a deep fryer, or fill a large high-rimmed pan or pot with enough oil to fill it by half, and heat to 170°C (340°F).
  • Peel and remove the tip from the onion, leaving the root intact. With the root facing up, slice next to the root to create 4 even slices around the onion in a cross shape. Slice in between each original slice to create 16 even-sized slices all the way around. Flip the onion over and gently open it to create a blooming onion (see photo and video).
  • Add all the flour mixture ingredients to a bowl and mix to combine.
  • In a separate bowl, whisk together the egg and milk to create an egg wash.
  • Dust the blooming onion in the flour mixture, making sure each individual layer is well coated.
  • Transfer the onion into the egg wash and coat well.
  • Place the egg-washed onion back into the flour, making sure everything is completely covered, getting in between each layer.
  • Gently place the dredged onion into the preheated oil and fry for 6-7 minutes, or until golden brown and extremely crispy. Remove and drain over a wire rack or paper towel.
  • Serve the crispy golden blooming onion alongside the tangy mayonnaise. Dig in.
Chef's Tips
Take your time slicing the onion into even layers — uneven cuts mean some petals cook faster than others, and the onion won't "bloom" open evenly.
Double dredge the onion (flour, egg wash, then flour again) and really work the coating into every layer — this is what gives it that thick, extra-crispy crust.
Don't overcrowd the oil or fry at too low a temperature — keep it at 170°C (340°F) so the onion crisps up quickly rather than absorbing excess oil.
Storage & Reheating
This is best eaten fresh and hot, as the crispy coating won't hold up well once stored. If needed, leftovers will keep in the fridge for up to 2 days; reheat in the oven or air fryer at 180°C (350°F) until hot through and crispy again, rather than the microwave, which will make the coating soggy. Because the mayonnaise contains raw egg, use a pasteurised egg where possible, especially for pregnant, elderly, very young, or immunocompromised eaters — it'll keep in the fridge for around 5-7 days rather than the couple of weeks you'd get from shelf-stable, store-bought mayo.
Serving 1OnionCalories 600kcalCarbohydrates 42.6gProtein 10.6gFat 43.7gSaturated Fat 6.5gPolyunsaturated Fat 5.89gMonounsaturated Fat 28.68gTrans Fat 0.1gCholesterol 89.4mgSodium 231.7mgPotassium 374.3mgFiber 2.6gSugar 7.9gVitamin A 181.93IUVitamin C 8.12mgCalcium 130mgIron 1.9mg