Prepare the cucumbers. Slice one large English cucumber very thinly (about 1/8 inch thick). You can use a mandolin, cheese slicer or sharp knife. Place the slices in a bowl or jar with the chopped dill.
Salt and press (optional but traditional). Layer the cucumber slices with a sprinkle of salt and press them under a second bowl or plate for 10 minutes. Pressing extracts excess water, allowing the cucumbers to absorb flavour and stay crisp.
Make the brine. In a saucepan, combine equal parts vinegar and water (about 1 cup each), ¼ cup sugar and 1 teaspoon coarse salt. Add 1 teaspoon peppercorns and any other whole spices you like. Bring the mixture to a simmer until the sugar dissolves. Pickle. Pour the hot brine over the cucumbers and dill in the jar. Let the mixture cool to room temperature, then cover and refrigerate for at least 30 minutes. The pickles will develop more flavour after a few hours and are best eaten within 5–7 days.
Serve. Use tongs or a fork to lift the slices from the brine. Drain them briefly before serving so they stay crisp.
