Truffle Smash Burger with Gruyère and Shallots
Two smashed beef patties with Gruyère and aged cheddar, caramelized shallots, arugula, and truffle aioli on a brioche bun.
- Prep
- 15min
- Cook
- 30min
- Total
- 45min
- Serves
- 2
- Calories
- 1020per serving, est.
By Time for Burgers, updated
Each burger gets two cheeses, one per patty: Gruyère for its nutty stretch, aged white cheddar for sharpness. The patties are smashed to 1/4 inch (6 mm) and cook in about 2 1/2 minutes total, so slice the cheese thin and lay it on the moment you flip.
Truffle oil is strong. The aioli uses 5 ml in 30 ml of mayonnaise, and adding more tends to make it taste harsh rather than earthy. Shallots, cooked slowly in butter and oil for 20 minutes or more, bring a softer sweetness than onions would, and a handful of arugula cuts through the richness.
Truffle Smash Burger with Gruyère and Shallots
Prep 15 min, cook 30 min, total 45 min. About 1020 calories per serving.
timeforburgers.com/recipes/midnight-truffle-smash-burger
Serves 2.
Ingredients
Instructions
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Make truffle aioli: whisk 2 tbsp mayonnaise, 1 tsp truffle oil, and ½ tsp lemon juice in a small bowl. Refrigerate until ready to use.
In a skillet over medium-low heat, melt 1 tbsp butter with 1 tsp olive oil. Add 8½ oz thinly sliced shallots and ½ tsp kosher salt, then cook for 20-25 minutes, stirring often, until soft, sweet and deep golden. Set aside.
Heat a cast-iron skillet or griddle over high heat and lightly grease with 1 tsp olive oil.
Divide 10 oz ground beef into 4 balls. Season the balls with ½ tsp kosher salt and ½ tsp black pepper, then place them on the hot surface and smash each with a sturdy spatula to about ¼ inch thick. Cook for 1½ minutes until edges crisp and char.
Flip the patties, then top half of them with Gruyère slices and the other half with aged cheddar slices. Cook until an instant-read thermometer in the center of a patty reads 160°F (71°C), about 1 minute more.
Toast brioche buns cut-side down on the skillet until golden, about 30 seconds.
Spread truffle aioli generously on bottom buns, stack two patties on each (one Gruyère, one cheddar), top with the caramelized shallots and 1½ oz baby arugula, and crown with top buns.
Tips
- Salt the beef balls just before they hit the pan. Salted too early, ground beef firms up and turns springy, like sausage.
- Lay a square of parchment between the spatula and the beef when you smash so the meat doesn't stick and tear.
- Shallots scorch faster than onions. Keep the heat at medium-low, stir often, and add a splash of water if they darken before they soften.
- Flip with a stiff, sharp-edged spatula, scraping under the crust so it stays on the patty, and check one for 160°F (71°C) before stacking.
Substitutions
- Swiss or fontina for Gruyère: a similar melt with milder nuttiness.
- No truffle oil: grate half a garlic clove into the mayonnaise with the lemon juice for a plain garlic aioli.
- A thinly sliced yellow onion for the shallots: it holds more water, so give it 30-40 minutes to caramelize.
Make ahead & storage
The truffle aioli and the caramelized shallots each keep 3 to 4 days covered in the fridge; rewarm the shallots in a small pan. Smash patties lose their crisp edges within minutes, so eat them right away; leftovers keep 3 to 4 days and reheat in a hot skillet to 165°F (74°C).
