Irish Pub Burgers with Whiskey Aioli (Pub-Style at Home)

Ingredients

• 1/2 cup (120 g) mayonnaise
• 1 tablespoon Irish whiskey
• 1 teaspoon Dijon mustard
• 1 small garlic clove, finely grated
• 1 teaspoon lemon juice
• 1/4 teaspoon smoked paprika
• 1/4 teaspoon fine salt
• 1/8 teaspoon black pepper
• 6 slices thick-cut bacon
• 1 tablespoon olive oil
• 1 large yellow onion, thinly sliced
• 1 1/2 lb (680 g) ground chuck, 80/20 or 85/15
• 1 teaspoon kosher salt
• 1/2 teaspoon black pepper
• 4 slices Irish cheddar cheese, about 4 oz (115 g)
• 4 pretzel buns, split and toasted
• 4 lettuce leaves, optional
• 4 tomato slices, optional