Slice radishes and blot them dry.Slice radishes on the thinnest setting on the mandoline slicer. You'll need a total of 28 radish slices. Blot to dry using paper towels.
Cut bread into circles using a round cookie cutter.Avoid cutting the crust. Aim to cut 2 circles out of each slice of bread using a round cookie cutter.
Assemble tea sandwiches.To assemble the base of the sandwich, butter a bread circle, top with a radish slice, spread butter on the top of the radish, then bread, then butter again. Generously butter the top of the sandwich where the radish rose will be placed.
Make radish roses.Take 6 radish slices and cut them in half so that you have 12 half circles. Fan out 4 radish half circles slightly so the pieces stagger a bit side by side. Take one end and start rolling. Place on top of buttered tea sandwich. Get 4 more radish half circles and fan out slightly. Place it around one side of the center of the radish rose. Get the last 4 half circles and place it around the other side.
To make 4 tea sandwiches, you'll need 28 radish slices (7 slices for each rose), and 8 bread circles.
7 radish slices in total are used to make 1 tea sandwich. 1 radish slice for the sandwich and 6 slices to make the radish rose.
Work the radishes 4 half circles at a time. Don't work with all 12 half circles to form the rose since it's too hard to work with that many at once. This part is the hardest. The radish slices are tiny, so they're hard to work with and they'll keep wanting to unroll.
You can use any size cookie cutter but I like to pick one that can cut out two circles from a slice of bread. I used a 2" round cookie cutter for this recipe.
Softened butter will make it easier to spread the butter onto the bread circles without tearing the bread.
Radish roses are frustrating to make so make sure you're not in a rush since you'll need a lot of patience.
Freeze bread then cut using a cookie cutter. It cuts more neatly than room temperature bread.
A mandoline slicer is key to making all the radish slices the same. Use the food holder thingy that comes with the mandoline so you don’t slice up your hand when you cut.
Radishes are pretty juicy so blot them dry by laying them out on paper towels. Damp radishes will make the bread soggy, which is a big no-no with tea sandwiches.
The butter adds flavor to the sandwiches and also creates a barrier between the bread and radish so the bread doesn't get soggy. It also holds the radish rose in place on top of the sandwich.