Caramelized Onion Toast
Whey Onions, Mornay Sauce, Tarragon, Sourdough
Chef Benjamin Tyson of Butterlamp Bread and Beverage | Nashville, TN
Adapted by StarChefs | May 2026 | Photo: Will Blunt
INGREDIENTS
Mornay Sauce:
100 grams butter
100 grams all-purpose flour
1 liter whole milk
250 grams shredded gruyère
Kosher salt
Whey Onions:
2 liters whey
2 white onions, julienned
Kosher salt
100 grams heavy cream
30 grams crème fraîche
Caramelized Onions:
30 grams grapeseed oil
1 red onion, sliced into ¼-inch rounds
1 shallot, sliced into ¼-inch rounds
25 grams butter
20 grams maple syrup
To Assemble and Serve:
Yield: 1 serving
1 slice sourdough bread
20 grams butter
Flaky salt
Tarragon vinegar
Chopped tarragon leaves
METHOD
For the Mornay Sauce:
In a small saucepan over medium heat, melt butter. Whisk in flour and cook 3 minutes. Remove from heat. In a separate saucepan over medium heat, bring milk to a simmer. Working in batches, whisk roux into milk until desired consistency is achieved. Working in batches, stir in cheese until fully melted and combined. Season with salt. Set aside.
For the Whey Onions:
In a saucepan over medium heat, add whey and cook until liquid is reduced by seventy-five percent. Set aside. In a stockpot over medium heat, combine onions and reduced whey. Season with salt. Cook 25 minutes, or until onions are soft and translucent. Add cream and bring mixture to a simmer. Stir in crème fraîche and 200 grams Mornay Sauce. Cook additional 10 minutes, or until desired consistency is achieved. Set aside.
For the Caramelized Onions:
In a large sauté pan over medium-high flame, heat oil. Add onions and shallots in an even layer. Cook until lightly browned. Add remaining ingredients. Using a pan press, sear 30 seconds. Using an offset spatula, remove alliums from pan and set aside.
To Assemble and Serve:
Heat oven to 350°F. On a parchment-lined sheet tray, spread butter on bread. Toast until golden brown. Flip and toast additional 1 minute. Top heavily toasted side with even layer Whey Onions and 5 Caramelized Onions. Toast until warmed through. Finish with salt, vinegar, and tarragon.
