In a blender or using a handheld blender, puree the milk (starting with 1 cup; see note), chia, cashews, cinnamon, vanilla extract, and sea salt until very smooth and thick (it will get thicker as it sits a little while and the chia swells). Prepare a nonstick skillet by wiping over with a touch of oil (you need a nonstick skillet, or this will be a sticky event!). Turn heat to high for a few minutes to heat up the pan, then reduce to medium/medium-high. Dip a slice of bread into the batter. Turn over and let it sit in the chia mixture for a few moments to soak, then remove and place in the skillet. Repeat with other slices, frying 2–3 pieces or more at a time, depending on the size of your skillet. Fry for 3–5 minutes on each side, until light brown. Keep the heat high enough to get a good sear/crust on the bread, but reduce if it’s scorching. Note that the slices will be sticky until they are ready to be flipped, so be patient. Repeat until all bread is used. Serve with fresh fruit and pure maple syrup.