Makes 2 focaccia

1 cup water
1 teaspoon active dry yeast
1 tablespoon (try with 1/2 T) coarse salt, divided
3 tablespoons sugar, divided (a coarse sugar, like demara, is nice for texture, but totally not critical)
1/4 cup olive oil, divided, plus additional for greasing the bowl
10 ounces (aka 2 1/4 cups) flour (can use 2 oz whole wheat)
1 large meyer lemon (or 2 smaller ones), washed and sliced as thinly as possible
2 teaspoons fresh rosemary needles