This soup, although it owes something to gazpacho, owes more to the kinship I have always sensed between cucumbers and watermelons. Slice one or the other, close your eyes, and take a whiff. Both vegetables evoke cool green lawns on warm summer days, which is exactly where and when this soup should be eaten.
- 2 medium cucumbers
- ½ sweet onion, such as Walla Walla
- 1 tablespoon rice wine vinegar
- 1 teaspoon sea salt
- ¼ teaspoon ground white pepper
- 3 cups (packed) seedless watermelon chunks
- 2 tablespoons sugar
- 2 teaspoons freshly squeezed lemon juice
- One ½-ounce packet unflavored gelatin
- 4 pinches black sesame seeds
1. Peel the cucumbers and cut each one in half lengthwise. Use a spoon to carve out the seedy center section of each half cucumber. Discard the seeds and cut the cucumbers into 1-inch pieces. Pile the pieces into a blender.
2. Peel the half onion and cut into 1-inch pieces. Put the onion into the blender with the cucumber pieces and add the vinegar, salt, and white pepper. Purée the cucumber soup and chill it.
3. Make the watermelon jelly. Put the watermelon chunks in a blender with the sugar and lemon juice and purée. Strain the purée to yield 2 cups watermelon juice.
4. Put ½ cup of the watermelon juice in a small saucepan and sprinkle the gelatin over the surface. Allow the gelatin to soften for 5 minutes, then put the saucepan over high heat and stir until the gelatin is dissolved and the juice is beginning to boil.
5. Put a pinch of sesame seeds into each of 4 paper cups. Stir the hot gelatin mixture into the remaining watermelon juice and distribute the mixture evenly among the 4 cups, pouring the mixture over the sesame seeds.
6. Chill the jelly in the paper cups until it is firmly set, about an hour. To remove the jelly from the cups, dip the cups one at a time in hot water and then invert them into a serving bowl.
7. To serve, invert one watermelon jelly into the center of each of 4 wide-rimmed soup bowls, then ladle about ¾ cup of the cucumber soup around each watermelon jelly. Serve cold.