Using a mandolin, slice paper thin shavings of fennel.
In a small bowl, mix fennel shavings with the lemon juice, honey, dill, and a pinch of salt. Taste and adjust seasonings. Let the fennel sit and marinate in the juices for a few minutes while you prep the rest.
Make the dill yogurt: Mix the yogurt, dill, lemon juice, agave, olive oil, garlic, if using, and pinches of salt and pepper. Taste and adjust seasonings. Chill until ready to use.
Grill or toast the bread, rub with garlic and sprinkle with salt if desired, and drizzle with olive oil. Assemble toasts with salmon or cheese, if using, marinated fennel, and a dollop of the yogurt.
Recipe by Love and Lemons at https://www.loveandlemons.com/lemon-ey-shaved-fennel-toasts/