Over the sink with your hands, press as much water as possible out of the tofu block. Now cube the tofu into about 1 inch by 1 inch sized cubes.
Add the full bottle of canola oil to a large pot. Use a pot with at least a 12 cup capacity—this will keep you from potentially getting hit by oil when it's hot. Heat over medium-high heat until when you look at the oil, it seems to be separating.
Turn the heat down to medium. With a slotted spoon or a fryer skimmer, lower a few pieces of tofu into the hot oil. I usually do seven cubes at a time, but start with less until you get the hang of it. The oil will probably go a little crazy, but if you've pressed enough water out of the tofu, it won't be too bad.
Let the tofu sizzle away in the oil. Every so often, use your slotted spoon or skimmer to move the tofu around to keep it from sticking to the bottom of the pan.
After about 2 minutes, use your spoon or skimmer to carefully remove a piece of tofu from the oil. If it looks crispy and golden brown, the tofu is done . Remove all the tofu pieces from the oil. If the tofu is not crispy and golden brown, place the cube back into the hot oil, and check again in another 1-2 minutes.
Note: you will have to adjust the temperature under the pot at times. If the oil is getting too hot and really going nuts, turn the heat down. If the oil gets too cold and is not making the tofu sizzle, turn the heat back up.
Once the tofu is crispy and golden brown, remove all the cubes from the oil with your slotted spoon or skimmer. Place on a plate lined with a paper towel to remove excess oil from the tofu. While the tofu is still warm, sprinkle with a little sea salt or fleur de sel.
Continue this frying process until all the tofu cubes are fried.