In a cocktail shaker, stir together the tequila, harissa paste, tomato juice, lime juice, Worcestershire sauce, celery salt, horseradish, onion and Tabasco. Divide among 4 ice-filled highball glasses. Garnish with Mini Sliders.
Preheat the oven to 400 degrees F.
Toss the cherry tomatoes with the horseradish, shallot and olive oil. Season with salt and pepper. Place the tomatoes in a baking dish and roast until they are just wilted, about 5 minutes. Allow to cool to room temperature.
Divide the ground beef into 4 even patties slightly wider than the buns (the beef will shrink during cooking); do not overwork the meat, handle it just enough to form the patties. Season the patties liberally with salt and pepper on both sides.
Heat a griddle or cast-iron pan over medium-high heat. Place a small amount of clarified butter or canola oil into the pan or griddle, and sear the burgers on both sides until charred. Transfer burgers to the oven and cook until they reach your desired temperature, about 4 minutes for medium rare.
Allow the burgers to rest for 5 minutes. In the same pan, toast the buns until golden brown. Brush one side of the buns with mustard, and place the patties on the buns. Top with slices of preserved lemon, followed by the tomatoes. Cover with the bun tops and skewer one cornichon on a wooden skewer and use it to secure the slider. Serve warm.