Fill a large mixing bowl with cold water and add a squeeze of lemon juice.
Slice the artichoke stalks into 1 1/2-inch pieces then cut the artichokes into quarters, removing the leaf ends any fuzzy parts. Immediately submerge the artichokes into the cold water to prevent it from going black.
In a large pot, add pork ribs, artichokes, fish sauce, sugar, salt, pepper and water. Bring to a boil then skim off any impurities for 10 minutes.
Reduce the heat to a low simmer and cover with a lid. Simmer for 45 minutes.
Always use a stainless steel knife and submerge sliced artichokes in cold acidulated water to prevent the artichoke turning black.