Blanch the broccoli florets in boiling water for 30-60 seconds, then run cold water over them or put them in a ice water bath to stop the cooking. Drain the water from the broccoli in either a strainer or salad spinner.
In a bowl or 4 cup measuring cup, whisk together the sweetener, mayonnaise, sour cream, salt, pepper, vinegar and lemon juice.
In a large bowl, combine the broccoli, onion, cheese, and bacon, the pour the dressing over it and gently fold with a spatula until combined.
Serve immediate or refrigerate over night to really bring out the flavor.
