Place a clay bowl or pot directly on medium-low heat and allow it
to heat up slowly*.
As the bowl is heating, add the oil and sugar and watch it
carefully; eventually, the sugar will melt and start to color. When
it’s a deep dark-brown caramel, add the shallots, ginger, and
shrimp heads, if you’re using them. Stir together for a minute and
then add the fish sauce, lemongrass, chili, shrimp, and a sprinkling
of black pepper.
Stir and cook until the shrimp are cooked through, 2 to 3
minutes; they’ll grow firmer and pinker as they cook. Add a little
water if it needs more liquid. Serve at the table in the clay dish
with steamed rice on the side.
* Clay bowls don’t like to be shocked.