Preheat the oven to 350 degrees F. Line a 14x17" baking sheet with parchment paper and set aside.
In a large bowl, mix together the kale, pumpkin, sunflower, sesame, chia, ground flaxseed, water, sea salt, rosemary, and garlic powder. Stir well, and let the mixture sit for 15 minutes so that the chia seeds can gel and help everything stick together.
After 15 minutes, transfer the mixture to the lined baking sheet and put another sheet of parchment paper on top. Use a rolling pin to roll the seed mixture until it's ~1/16" thick. Remove the top sheet of parchment paper and transfer the baking sheet to the middle rack of the oven. Cook for ~25 minutes, until the crackers get slightly brown around the edges.
Remove the baking sheet from the oven and use a pizza slicer to cut into 25 crackers. Then carefully use your fingers or a fork to turn over the crackers. Put them back in the oven for another 5-10 minutes so that they firm up a bit more. Keep a close watch on them so that they don't burn.
Let the crackers cool completely before eating. Serve with cream cheese, regular cheese, nut butter, or hummus. Store in an airtight container in a cool, dry place for up to a week.