Caramelized Onions And Broccoli Recipe Caramelized Onions and Broccoli Ingredients: butter (stir-fry amount) onion broccoli head brown sugar soy sauce 0. Chop onion into thin pieces. Peel apart broccoli into slightly larger pieces. Do not behead the broccoli. 1. Melt the butter in a pan on high heat. 2. Add broccoli to the pan. Stir for a bit. 3. Add onion to the pan. Stir for a bit, then reduce heat to medium high. 4. After a few minutes, add the brown sugar and soy sauce, in whatever quantities correspond to the intended sweetness and saltiness. Stir to ensure the sugar melts and both coat the vegetables brownly. 5. Continue stirring for a few minutes, until the sweet flavor of the onions emerges, and then stop. There will be leftover soy sauce/brown sugar; pour it over the vegetables.