Pre-heat oven to 350 degrees and toast pine nuts on a baking sheet until golden brown, 5-7 minutes; set aside.
Remove the stems and halve Brussels sprouts then place in a food processor. Pulse until roughly chopped or use the slicer attachment to thinly slice. Alternatively, you can use a mandolin or simply thinly slice with a knife.
In the bottom of a large bowl, whisk together the tahini, lemon juice, grated garlic, salt and pepper. Slowly stream in up to 1/4 cup of warm water until you've reached a slightly thin and creamy consistency.
Add chopped Brussels to the bowl and toss to coat in the tahini dressing. Stir in the dried cherries and toasted pine nuts; set aside.
To prepare the crostini, spread baguette slices in an even layer on a baking sheet and brush with olive oil. Sprinkle with za'atar and a pinch of kosher salt. Bake until golden brown, 7-9 minutes.