1. Prepare the Blooming Onion:
- Cut the top of the onion off, leaving the root intact. Peel the onion, and cut about 1 inch from the bottom, creating a flat base.
- Using a sharp knife, make vertical cuts into the onion, starting from the top, leaving about 1/2 inch from the root intact.
- Turn the onion and make another set of vertical cuts, creating sections or petals.
- Soak the onion in buttermilk for at least 30 minutes to help separate the petals.
2. Prepare the Coating:
- In a bowl, combine the flour, cornstarch, paprika, cayenne pepper, garlic powder, dried oregano, salt, and black pepper.
- Mix the dry ingredients well to create the coating mixture.
3. Coat the Onion:
- Drain the buttermilk from the onion and carefully open the petals to expose the inner layers.
- Dredge the onion in the seasoned flour mixture, ensuring the coating gets between the petals.
- Gently shake off any excess flour.
4. Fry the Blooming Onion:
- Heat vegetable oil in a deep fryer or a large, deep pot to 350°F (175°C).
- Carefully lower the coated onion into the hot oil, root side down.
- Fry for about 3-5 minutes or until the onion is golden brown and crispy.
- Remove the blooming onion from the oil and let it drain on paper towels.
5. Prepare the Dipping Sauce:
- In a small bowl, mix together mayonnaise, ketchup, creamy horseradish sauce, paprika, salt, and black pepper.
- Adjust the seasoning to taste.
6. Serve:
- Place the fried blooming onion on a serving plate and serve it with the dipping sauce.
Enjoy the Outback Steakhouse Blooming Onion experience right in your own home!