Blanch the rhubarb in the microwave quickly. ( take a casserole dish with a lid, place 1/4 cup of water in the bottom, add the rhubarb and then steam for 4-5 minutes until it's softer.)
Take your strawberries and rhubarb and using a food processor or hand blender puree them well.
Add 2-3 tbsp of honey to the mixture, depending on how sweet you want it.
Line a cookie sheet with plastic wrap.
Spread the puree evenly to just a 1/4 inch thickness, making sure there is plastic showing all the way around the edge of your sheet. The puree can be dried in a 150 degree Fahrenheit degree oven or in a food dehydrator. If you like, you can turn your oven on as low as it can go every hour, then turn it off and let the residual heat dry out the leather. You are not cooking it at all, there is no "safe temperature“ other than please don't crank the oven UP- so to save electricity you don't have to leave the oven on continuously. But DO leave it shut to keep that heat in. This can take anywhere from 6-8 hours in the oven.
When the leather peels away from the wrap, is still slightly tacky when you touch it but your finger doesn't leave a mark, it is done. You can roll it right up in the plastic and cut it into little rolls. They will stay in the fridge for up to a month!
All calories and info are based on a third party calculator and are an estimate. Actual nutritional info will vary with brands used, your measuring methods etc.