using a mandolin slice oranges, kumquats to 1/8 inch, removing seeds as you go. Stack and slice in quarters (or so that the peels are about 1/2 to 1 inch long). Place orange and kumquat in LARGE pot with water and allow to rest for 1 hour. Place small plate in freezer.
Slice strawberries to 1/8 inch and smash EXTRA CHUNKY. Add to water mixture and bring to full boil. Reduce heat to a simmer and cook for 40 minutes stirring often.
Bring back to boil, add sugar and continue to boil until temperature reaches 222F. This will take about 15 - 20 minutes. To check for doneness, drip about 1 TBSP on frozen plate. Wait about 30-45 seconds. If it starts to gel, it is done. If not, cook for a bit longer or until temp reaches 224.
Meanwhile, while you're waiting for the temp to get to 222, prep your mason jars and lids (I used 4 1/2 8 ounce jars...Just prep more than you think you'll need) in boiling water. Remove jars, lids and rings from water and drain on towel until ready to use.
Fill jars to just to the bottom of the rings, place lids on and set on counter to cool for at least 12 hours.
Will last for 6 months in cool dark place, with lids sealed. Once opened, store in refrigerator for up to 2 months.