Heat a medium skillet over medium heat. Add the onions to the hot pan with Braggs aminos. Spread the onions evenly over the pan. After 10 minutes, sprinkle over a pinch of salt. Add a little bit of the beef broth at a time to the pan, approx. 1 to 2 Tbsp at a time.
Let the onions cook for another 30 minutes, add more beef broth until it’s evaporated. Be sure to let the onion brown before stirring. Remove from heat once caramelized.
In a large bowl, combine chicken, garlic, fennel, sage, and lemon juice. Use your hands to make sure all the ingredients are evenly distributed. Form the mixture into 4 sausage patties and set aside.
Heat a large skillet over medium-high heat. Once the pan is hot, add patties and cook until golden brown on both sides, approx. 3 to 4 minutes per side. Set aside and keep warm.
Bring a large pot of water to a boil. Once boiling, add cauliflower. Boil until tender, approximately 15 minutes. Reserve 1/2 cup of cooking liquid. Drain the cauliflower and add to a high power blender or food processor.
Add 1/4 cup of the reserved cooking liquid to the cauliflower with 1/2 tsp salt. Puree until smooth. If the mixture is too thick, add more water 1 Tbsp at a time until desired consistency.
Divide the cauliflower mash between two bowls. Top each bowl with two chicken sausages and half of the caramelized onions. Serve immediately.