Peel and chop potatoes into small pieces.
Heat a skillet, and add olive oil. When skillet is hot, turn heat down to medium and add all the chopped potatoes. Cook and stir until edges begin to brown.
Chop one bell pepper, and add this to the potatoes. Continue to cook for about 5 minutes, or until potatoes and peppers begin to soften.
In a bowl, crack the four eggs and whip slightly to combine. Add the eggs to the skillet on top of the peppers and potatoes.
Push eggs around as they begin to set and cook, until the eggs are no longer runny. Season with salt and pepper, if desired. Toast the four slices of bread and serve with eggs and watermelon on the side.