Deseed the cucumber and peel (if required). Dice or grate the cucumber. Wrap the cucumber in a paper towel or kitchen towel - squeeze excess liquid. Set aside.
Peel and mince the garlic (1 or 2 cloves depending on the size and how garlicky you like your tzatziki). Chop the dill (and parsley if using).
Whisk all ingredients together in a small bowl (including any optional ingredients). Taste and adjust seasonings as desired.
Store in an airtight container or jar in the refrigerator for 4-5 days.
Instructions for the Cashew Base Option
Add ½ cup raw cashews, 2 tablespoons of water, apple cider vinegar, lemon juice, and garlic cloves to a high speed blender. Blend until smooth and silky.
Transfer the cashew sauce to a bowl, add the prepared cucumber, chopped dill, salt, pepper (onion granules and parsley if using), and whisk together. Taste and adjust seasoning to your personal preference.
Pro Tip: because the cashews have a natural sweetness, I typically use apple cider vinegar and/or white vinegar in place of lemon juice. And an extra pinch of salt.
Store in an airtight container or jar in the refrigerator for 4-5 days. Tzatziki sauce thickens as it chills.
Notes
Dairy-free mayonnaise: I love Vegenaise but any vegan mayo will work.Cashew cream or yogurt base: Sub in an equal amount of thick cashew cream or Greek style non-dairy yogurt for the Vegenaise.Cucumbers: I use the mini or Persian cucumbers they are the perfect size for this tzatziki sauce, have thin skin (leave the peel on) and a low seed content. Add more cucumbers for a chunkier sauce OR less for a smoother texture.Garlic: Add more or less garlic to taste. I use 1 large garlic clove or 2 small.Lemon juice: Use freshly squeeze lemons, white or apple cider vinegar for the tanginess.Dill: Fresh is best, but use dry dill in a pinch. If using dry, start with 1 teaspoon, stir together, taste and adjust to your preference.Storage: Keep refrigerated in a jar for up to 5 days.