Get a fresh Broccoli and cut it into in florets. While making florets keep in mind, do not keep too much of the stem. Cooking time of stem is different than the flowers, stem takes longer to cook.
Boil water in a pot with salt added generously and simultaneously in a separate bowl, add tap cold water and lot of ice to make the water chilled.
When the water starts boiling add broccoli for 1 to 2 mins, do not exceed more than 2 mins to avoid over-cooking. Within 1 to 2 minutes, strain the broccoli and add the hot boiled broccoli to iced water. You will see the broccoli will be cooked and still retain its bright fresh green color. Strain it from cold water, and you can eat it cold, or heat it again by just sautéing it as below or add it in your stir-fry.
You can use this method with spinach, beans, collard greens, etc.
You can further season the broccoli as below:
Heat olive oil in a pan and add chopped garlic about 2 cloves, chili flakes 1/2 tsp (you can adjust this as per your taste).
Now add chopped onions 1/4 cups sauté the onions and add boiled florets. Sauté it for 2 to 3 minutes and serve it hot as a side dish.