Run a lime wedge around the rim of a short rocks glass. Dip the rim into a small plate with the coarse sea salt so it picks up an even, thin coating. Set the glass in the freezer while you make the cocktail to chill.

Mix Cocktail

Add the mezcal, reposado tequila, blue curaçao, fresh lime juice, agave syrup, egg white, and orange bitters to a cocktail shaker (without ice).

Dry Shake

Seal the shaker and shake vigorously for 15–20 seconds to emulsify the egg white and create a silky foam.

Wet Shake

Open the shaker, add the shaking ice (about 6 large cubes), reseal and shake hard for 12–15 seconds until the shaker is very cold to the touch and well mixed. This both chills and dilutes the drink and builds a stable foam.

Strain the cocktail through a fine mesh strainer (double strain if possible) into the chilled, salt-rimmed rocks glass over a single large serving ice cube.

Finish & Garnish

Gently float an additional small drop of blue curaçao in the center of the foam if you want a striking 'blue crystal' dot. Alternatively, sprinkle a pinch of edible blue sugar or place a small piece of crystallized blue candy on the foam for a Walter White-inspired look.

Garnish with the lime wheel on the rim or floated alongside the ice. Serve immediately.