Rau câu, or thạch or xu xoa is a jelly with agar. Agar,a product from certain seaweeds, is also called agar-agar or Chinese gelatin or Japanese gelatin which is a substitute for gelatin specially in vegan, vegetarian diet. They are sold as powder (off white color), dried strips, or spongy box-shaped cuboids. Powder is easy to measure by volume. A small package of agar powder is 0.88 oz (25 gr) about 9-10 tsp. You can find it at oriental stores in town. It has a very long shelve life in dry, air tight container.
Make 4 servings ( about a cup size)
- 2 tsp agar powder
- 2 cups water
- 4-5 Tbs granulate sugar
- 1 cup milk or coconut milk
- 1 large or two medium ripe mango
- Maraschino cherries for garnish (optional)
- Peel mango, cut and save two thin slices (1/8 inch thick) to garnish and cut the rest in small chunks, discard the seeds. Place mango chunks and milk into a blender. Puree until smooth. It should be at least 2 cups, if not add more milk/coconut milk. If mango has a lot of strings, strain the mango mixture through a sieve if you want too.
- Add water in a medium saucepan. Sprinkle agar into water. Stir and bring it to a boil over medium high heat. Add sugar, stir and turn the heat down to medium low or low. Simmer and stir constantly until agar dissolved 2-3 minutes.
- Stir mango mixture in and bring it back to boil. Turn off the stove and remove from heat immediately. Pour into serving glasses, cups, etc. or pour it into small molds or a large container.
- Garnish with mango slices and cherries when the surface is firm to the touch (a few minutes). Let stand until cool. Refrigerate until jelly is firm and cold few hour or overnight. Cut into squares, rectangles or diamond shapes if using a large container. Serve chilled.