1) Toast the bread slices lightly, then allow to cool.
2) Spread 2-3 tablespoons of tzatziki sauce on each slice of toast, then add a generous layer of the shaved Castello Dill Havarti Cheese.
3) Add a layer of heirloom tomato slices, varying the colors as desired. Drizzle the tops with olive oil and finish with salt and pepper to taste. Garnish with fresh dill, mint, and thinly sliced chives and enjoy.