No it would be a terrible idea. You would become bored and dissilusioned quickly, and also by narrowing your nutritional scope, you run a greater chance of missing out on essential nutrients, ie. if you choose veg that is consistently low in vit D, then over time you will become defficient in that vitamin.
Vary your diet as much as possible, use herbs and spices to give flavour instead of sauces and salt.
Make sure you have sensinle quantities of carbohydrate (rice, pasta, cereals, potatoes, bread) and adequate amounts of protein (beans, pulses, fish, poultry, lean meat, eggs), reduced fat dairy produce and 5 varied portions of fruit and veg per day.
There is so much good natural food out there, why make life boring?