Preheat oven to 200F.
Line a pan with parchment paper cut to fit. Set aside.
Peel and then thinly slice the bananas at an angle, and place on the pan. Make sure the bananas don't touch or overlap. Squeeze lemon juice all over.
Bake in the oven at 200F for 1 hour.If you cut the bananas super thin, they'll be done at this 1 hour mark. Taste a piece to check. If you feel they need to cook longer (or you prefer the bananas to be more crispy), remove the oven from the pan. Flip each banana slice over. Then bake for another 30 minutes. Remove from the oven and let cool. Remove the bananas from the pan. Eat and enjoy ^_^