Name: LongHorn Texas Tonion Copycat Recipe
Prep time: 25 min
Cook time: 10 min
Total time: 35 min
Yield: 4 servings
Cuisine: American
Ingredients: 2 large sweet Colossal yellow onions; 2 cups buttermilk; 3 cups all-purpose flour; 2 tbsp cornstarch; 1.5 tbsp salt; 1 tbsp garlic powder; 1 tbsp onion powder; 1 tbsp sweet paprika; 1 tsp cayenne pepper; Vegetable oil (for deep frying); 1/2 cup mayonnaise (for sauce); 2 tbsp ketchup (for sauce); 2 tbsp creamstyle horseradish (for sauce); 1/2 tsp cayenne pepper (for sauce); 1/2 tsp paprika (for sauce); 1/2 tsp garlic powder (for sauce)

Why This Copycat Recipe Works

The Texas Tonion® is a giant onion fried in sweet-savory petals rather than a singular bloom. LongHorn makes this dish by using sweet Colossal onions, double-dipping the petals in seasoned flour and buttermilk, and serving it with a zesty horseradish sauce. Sweet Colossal onions have a milder, sweeter flavor that caramelizes beautifully under high-heat frying. Our recipe shows you how to prep and fry these petals to get maximum crunch, alongside the copycat sauce recipe.

Reviewer Rating: ⭐⭐⭐⭐⭐ (4.7/5 from 28 reviews). Last Updated: July 2026.

Prep Time	Cook Time	Total Time	Servings	Est. Price per Serving
25 minutes	10 minutes	35 minutes	4 servings	~$2.00 (vs $13.49 at restaurant)

Step-by-Step Instructions

1. Slice the Sweet Onions

Cut the stem off the top of the onions, peel them, and slice them vertically into thick 3/4-inch slices. Separate these slices into individual curved petals. Discard the very small center layers (save them for cooking other dishes).

2. Soak the Onions

Submerge the onion petals in a large bowl filled with 2 cups of buttermilk. Cover and soak in the refrigerator for at least 30 minutes (up to 2 hours). This reduces the sharp sulfuric onion bite, making the petals sweet and tender.

3. Make the Copycat Tonion Sauce

In a small bowl, whisk together the mayonnaise, ketchup, cream-style horseradish, cayenne pepper, paprika, and garlic powder. Cover and refrigerate. The sauce flavors meld together best if chilled for at least 30 minutes before serving.

4. Prepare the Seasoned Flour Coating

In a large dry bowl, combine the all-purpose flour, cornstarch, salt, garlic powder, onion powder, sweet paprika, and cayenne pepper. The cornstarch is a secret trick that makes the batter extra light and crisp.

5. Double-Dredge and Fry

Heat deep frying oil (vegetable or canola) to 375°F (190°C) in a large Dutch oven. Dredge a handful of onion petals in the flour mix, shake off excess, dip briefly back in buttermilk, then dredge in flour again. Fry in small batches for 3 to 4 minutes until golden and crispy.

6. Drain and Serve

Drain fried petals on paper towels. Serve immediately piled high on a platter with the chilled zesty horseradish sauce.

Cooking Tips & Variations

Onion Selection: Vidalia onions, Walla Walla sweet onions, or Texas Sweet onions are the best options. Red onions or white onions are too sharp for this recipe.
horseradish levels: The copycat sauce relies on cream-style horseradish for its punch. Adjust the quantity to control the nasal heat level. Start with 1 tablespoon and increase to taste.
Air Fryer Version: Spray double-coated petals generously with cooking oil spray. Air fry in a single layer at 375°F (190°C) for 10-12 minutes, shaking gently and spraying with oil halfway through.

Nutrition & Price Disclaimer

Menu prices and nutrition estimates represent the standard LongHorn Steakhouse recipe verified in 2026. A restaurant serving contains approximately 1,450 calories and 2,200 mg of sodium due to deep frying. Sharing across a group reduces individual intake significantly. Homemade values vary based on the cooking oil absorbed. Check the official menu at longhornsteakhouse.com.