1 1/2 to 2 teaspoons fine salt can be used in place of the kosher salt.
Use black pepper instead of white if needed.
If you do use shallots, note that a little will go a long way because they go in raw. Feel free to saute them in a little butter to take off the sharp, raw edge. Besides shallots, some thinly sliced green onions would be great, as would sauteed leeks, or even just finely minced yellow onions.