Grate the raw beet using the biggest holes on a box grater and transfer to a food processor.
Add sugar, salt, juniper, and peppercorns to the food processor and pulse until sandy.
Mix in lemon zest, dill, and tarragon with your hands.
Splash gin on salmon and coat evenly.
Layer beet-salt mixture on salmon, wrap tightly in plastic and parchment, then weigh down with baking sheets and weights.
Refrigerate for 16-18 hours, flip salmon, reweigh, and refrigerate another 16-18 hours.
Rinse and pat dry the cured salmon, slice horizontally between skin and flesh.
Serve with eggs, pasta, toast, or cream cheese.