Prep the Potatoes
Slice clean potatoes into ¼ inch thick rounds and transfer to a large pot. Cover with cold water and add a big pinch of salt.
Bring to a boil over high heat, then reduce and simmer for 10 to 15 minutes or until potatoes are fork-tender. Drain and rinse with cool water.
Prep the Salad
Slice achocha cucumbers in half lengthwise, quarter tomatoes, and peel gooseberries.
Make the Vinaigrette
Add half of the gooseberries, vinegar, olive oil, salt, and pepper to a blender. Blend until the vinaigrette is smooth and emulsified.
Bring it all Together
Dress potatoes, cucumbers, and tomatoes in vinaigrette tossing to coat.
Plate dressed vegetables and garnish with reserved gooseberries, celery leaves. Finish with sea salt and fresh cracked black pepper to taste.