The Filipino sour soup known as Sinigang can contain any variety of meats, poultry and seafood, and is typically studded with a variety of local vegetables. Depending on the region of the Philippines, a range of native fruits can be used to give Sinigang its trademark tang. And although vinegar is a vital ingredient in Filipino cooking, it is never used as a souring agent for Sinigang.
The typical souring agents that can be used include unripe tamarind pods and leaves, kamias (a very sour green fruit pod native to the Philippines), guava, starfruit, tomatoes, as well as lemon, calamansi and dayap (another variety of Philippine lime).
But since Rhubarb is so plentiful this time of year in my neck of the woods (and also because tamarind, kamias, guava, starfruit and dayap don't grow in my neck of the woods), I decided to try and use the sour red stalks to bring the tang for a Pork Sinigang.
Rhubarb? In soup? Yes. And it works wonderfully! Although rhubarb is typically used in desserts, a savory Sinigang application isn't as crazy as it sounds. Besides lending the necessary sourness for a proper Sinigang, rhubarb also provides a nice crunchy texture in much the same way that daikon or taro traditionally would in the Filipino sour soup.
And besides, using Rhubarb in Sinigang will trip out even the most palate-progressive of all your Filipino friends. It's a culinary curveball!