Preheat the grill to 350°F.
To prepare the pickled cucumbers, put the cucumber in a bowl or container that will fit in the refrigerator. Add the rice wine vinegar, sea salt, red crushed pepper stevia and rest of the spices. Place plastic wrap in the bowl over the cucumber mixture and slowly slide it down until it is flush with the liquid. Refrigeratate for at least 1 hour. The longer it sits, the more the flavor builds. Youmay do this step at least 24 hours in advance.
Place frozen burger directly onto grill and cook until juices come through. Flip burger and cook until the internal temperature reaches 160°F. Transfer to a baking sheet, top each patty with a slice of Havarti.
To build each burger, place a lettuce leaf on each of 4 plates. Put a cheese-covered patty on the lettuce, place a tomato slice on the patty then add onion slices. Top with onions and pickled cucumbers, fan the avocado slices over them and finish with another lettuce leaf. Enjoy!