3 tsp sherry vinegar or red wine vinegar, divided
¾ cup almonds, divided
1 garlic clove, chopped
½ cup extra-virgin olive oil
Flaky Sea salt
Preheat oven to 350°F. Cut cucumbers about 1" thick on a steep diagonal and place in a medium bowl. Add a large pinch of kosher salt and 2 tsp vinegar and toss to combine; let marinate 10 minutes. Pour off any liquid that is released.
Toast ¼ cup almonds on a rimmed baking sheet, tossing once, until golden, about 5 minutes. Let cool, then coarsely chop. Set aside.
Blend garlic, oil, remaining 1 tsp vinegar, remaining ½ cup almonds, and ½ cup ice water in a blender until smooth and creamy, about 2 minutes; season generously with salt.
Divide sauce among plates and top with cucumber salad and chopped almonds. Sprinkle with flaky sea salt.
Do Ahead: Sauce can be made 1 day ahead. Cover and chill.
Recipe adapted from: https://www.bonappetit.com/recipe/cucumbers-with-ajo-blanco-sauce