Combine the garlic, vinegar, red pepper flakes, lemon zest, and lemon juice in the bottom of a salad bowl, whisk to combine. Stream in the olive oil while whisking, until emulsified. Add a generous pinch of salt to taste and adjust if needed. Set aside.
Grind the cashews in a mortar and pestle until mostly fine. Add the nutritional yeast, a generous amount of both black pepper and salt right to the mortar bowl, and mix to combine.
Place the fennel on a mandoline stem side down, root facing up (see photo) and slice very thinly right into the bowl with the dressing. Cut the fennel in half through the root if it doesn't fit on your mandoline and proceed to slicing. Avoid the tough core by rotating the fennel when slicing, at the end. Add the white beans, reserved fennel fronds, and about half of the cashew dust to the bowl, and mix to combine. Serve right away, finished with more cashew dust.
Notes
To customize this recipe, you can use other kinds of beans, or add in delicate greens like arugula or herbs, and/or citrus segments. Rustic, homemade croutons would also be really good here.
Recipe by Golubka Kitchen at https://golubkakitchen.com/versatile-fennel-salad/