Avocado with Radish and Carrot and Pickled Onion

Name: Avocado with Radish and Carrot and Pickled Onion
Ingredients: ¼ small red onion, finely chopped; ¼ cup fresh lemon juice; ½ teaspoon kosher salt; 1 garlic clove, finely grated; 3 tablespoons finely chopped fresh parsley; 1 tablespoon finely chopped fresh mint; 1 tablespoon finely chopped fresh tarragon; 3 tablespoons olive oil; 2 teaspoons fresh lemon juice; Kosher salt; 2 ripe avocados, thinly sliced; 1 medium carrot, peeled, shaved into ribbons with a vegetable peeler; 1 breakfast radish, trimmed, very thinly sliced on mandoline; 1 red radish, trimmed, very thinly sliced on mandoline; 1 tablespoon olive oil; 1 teaspoon fresh lemon juice; Smoked or flaky sea salt