According to the inquiry of the gourmet world, there are several remedies for forgetting to put the dried Chili in the beef brisket when it is cooked:

If you haven't cooked it yet, you can add a proper amount of dried Chili or Chili sauce to the pot and cook it for a while to let the beef brisket absorb the spicy taste.

if you are out of the pot, you can cut the beef brisket into small pieces, put it in a container, add dried Chili or Chili sauce, mix well, and put it in a microwave oven or steamer to heat it, so that the beef brisket can taste again.

if you don't want to heat the beef brisket, you can make a small dish of dried Chili or Chili sauce, put it next to the beef brisket, and dip a little when eating it, which can also achieve a spicy effect.