• First prepare the spread. Remove the pit from the avocados, and scoop into a food processor along with the lemon juice and salt. Puree until completely smooth, scraping down the sides ith a rubber spatula as necessary. Add the cucumber and pulse until cucumber is finely chopped. Add the mint and dill and pulse again so combine. You just want them well incorporated into the mid, not pureed.
• Let the mixture sit for 10 minutes or so to let the flavors marry, and then taste for salt and seasonings.

To assemble:

• Arrange the sliced of bread on the counter. Spread the avocado mixture onto all 12 slices. Add a single layer of cucumber on 6 of the slices. Now close each sandwich. Use a steak knife to cut off the crusts. With a gentle touch (so as not to squish the filling out too much), cut each sandwich into 4 equal pieces, either squares or triangles. Serve topped with extra herbs, or lettuce. In this pic, I topped them with pea shoots.