Diner Burger & Fries

• 2 large egg yolks
• 2 tablespoons fresh lemon juice, divided
• 1 cup grapeseed or vegetable oil

Kosher salt

Vegetable oil (for frying; about 8 cups)

• 3 pounds Yukon gold potatoes (about 8), cut into ¼" sticks

Kosher salt

• 2 pounds ground beef, preferably ground chuck (20% fat)

Kosher salt, freshly ground pepper

• 4 slices aged white cheddar
• 4 soft brioche rolls, split, toasted
• Bibb lettuce and pickled red onion (click here for recipe; for serving)

A deep-fry thermometer

1. Whisk egg yolks and 1 Tbsp. lemon juice in a medium bowl. Whisking constantly, gradually drizzle in oil, drop by drop at first, until mayonnaise is thickened and smooth. Whisk in remaining 1 Tbsp. lemon juice; season with salt. Cover and chill.
2. Do Ahead: Mayonnaise can be made 1 day ahead. Keep chilled.
3. Fit a medium saucepan with thermometer; pour in oil to measure 2". Heat over medium-high heat until thermometer registers 350°. Working in 4 batches, fry potatoes, turning occasionally, until golden and tender, 6–8 minutes; transfer to a wire rack to drain.
4. Just before serving, working in batches, fry potatoes until golden brown and crisp, about 4 minutes. Transfer to wire rack and season with salt.
5. Do Ahead: Potatoes can be fried once 4 hours ahead. Leave on rack at room temperature.
6. Meanwhile, prepare a grill for medium-high heat. (Alternatively, heat a cast-iron skillet over medium-high heat.) Divide meat into 4 portions and form into into 4" patties. Using your thumb, make a small indentation in the center to help keep the burger flat as it cooks. Season generously with salt and pepper.
7. Grill burgers, rotating every 2 minutes, about 4 minutes per side for medium, topping with cheese during last 2 minutes of cooking.
8. Place burgers on buns and top with lettuce and onion. Serve with lemon mayonnaise and fries.