High West Allston Cocktail with garnishes

1 oz High West 7000'
1 oz Tanquery 10
0.5 oz Green Chartreuse
0.5 oz Lemon Juice
0.25 oz Simple Syrup
2-3 Dashes Peychaud's Bitters
1 Egg White
2 oz Fever Tree Soda Water
Peychaud's Bitters Garnish

Chill an Old Fashioned glass. Add all ingredients except soda water to a cocktail shaker and shake with cube ice until chilled. Strain back in to the cocktail shaker, discard the ice and shake again (dry reverse shake). Double strain into the chilled Old Fashioned glass and top with chilled soda water. Garnish with 4 drops of Peychaud's Bitters.