 Depending on the method used, cooking can take from a few minutes to over two hours.If the watermelon is baked, a texture like raw fish can result, "Boston Phoenix" writer Robert Nadeau comparing a grilled watermelon to seared, raw tuna.He added that the flavor of the fruit "isn't sweet, although it isn't meaty either, but enough of the browning comes through to make it a little like a piece of meat".