Spray an 8 inch ( 20 cm) non stick skillet with cooking spray. Heat skillet over medium high heat. Add ham and onion and saute until onion is tender; set aside. Generously spray skillet again with cooking spray and cook potatoes over medium heat until tender and golden brown. Beat together eggs, water, salt and pepper in a bowl; pour over potatoes. As eggs begin to set, lift mixture on top. Sprinkle with cheese; cover skillet to melt cheese. Cut into wedges and serve with tomato chutney.