Grate a cucumber and place in a napkin in a strainer. Squeeze out as much water as possible.
Then add the squeezed grated cucumber, yogurt, fresh dill, grated garlic clove, ¼ t kosher salt and 1 t lemon juice together and combine. Taste and add ⅛ t more kosher salt as needed.
In the meantime, unthaw the gyro meat until partially frozen. Add the meat to the pan and place it over medium heat covered with a lid until the fat from the meat begins to render out. Remove the lid and allow the meat to cook until thoroughly heated and nicely browned about 6-7 minutes.
Prepare the vinaigrette by combining the oregano, basil, marjoram, 1 ½ T lemon juice, white vinegar, a grated garlic clove and salt together. Add the olive oil and mix again.
Fill each bowl with 1.5 cups of the spinach/kale blend, then top each evenly with ½ of the large cucumber sliced, as well as the cherry tomatoes sliced in half. Top evenly with the meat (about 2 oz per bowl). Give each bowl a scoop of tzatziki sauce and drizzle the whole bowl with the herby Greek vinaigrette.