Over medium heat, toast the mustard seeds and peppercorns in a large saucepan. Cook until fragrant, about 2 minutes.
Add the water, vinegar, sugar, and salt to the pot. Simmer for 10 minutes.
While simmering, cut your cucumbers in your desired shape. Make sure spears fit inside the jar (cut off an end if not). Put the pickles and brine in mason jars or another seal-able container.
Remove from the heat. Add the dill to the liquid and pour the liquid into the mason jars, covering the cucumbers. (If you want crunchier pickles, let the liquid cool BEFORE adding the pickles so the heat does not cook them).
Keep chilled, ideally for at least 10 hours before eating. Pickles can be kept up to a month.
Notes
This made enough to fill three pint sized mason jars.Try to find cucumbers that are just long enough to fit in the jar. But if they are too long, you can chop off one of the ends for them to fit as spears.Kirby cucumbers are best for pickling, but you can experiment with different types.I love wavy pickle coins, so I use a mandolinewith a wavy blade. (I have struggled finding a good mandoline in the past and have found my favorite mandoline with many blades and adjustable thickness).The volume of pickles you get will vary greatly with how you cut them. If you cut each cucumber into 8 spears, you will have 32 final spears.