Grate the zucchini in a food processor or high-speed blender.
Steam the cauliflower for about 5 minutes until just fork tender. Add the cauliflower to the food processor/blender and process until broken down into small chunks. Do not over process or it will become a mash.
Use a dishtowel or nut milk bag to squeeze as much moisture as possible out of the grated veggies.
Transfer to a bowl and add the flour of choice, egg. salt, pepper, and any other seasonings you like. Mix to thoroughly combine. Shape into eight patties.
Add oil to a large pan. Add four fritters to the pan and cook over medium heat for 2-3 minutes per side. Repeat with the second half of the fritters/burgers.
Serve with dipping sauce of choice.
Notes
TO STORE: Place leftovers in an airtight container and store in the refrigerator for up to one week. TO FREEZE: Let the fritters cool completely then place them in a ziplock bag and store in the freezer for up to 6 months.