Based on the context and the answer, generate a question. 

Context: Add the onions and some salt sweat until sweet and translucent . Add the peas and defrost in the skillet with the onions . When the peas are fully warmed , turn off the heat of the skillet . Add the yogurt , tarragon and pistachios .

Answer:

The onions need to be cooked longer .



Why are the onions added first ?