Finely shred the vegetables, using a vegetable peeler, to make long but thin strands. Rotate the vegetable as you work, so that you're always on the edge of the vegetable - the thinnest strands are made this way. If you have a mandolin, go for your life.
Super-quick White Sauce:
3 Tbsp margarine/butter
3 Tbsp white flour
1 & 1/2 to 2 & 1/2 cups Soymilk/milk
Melt the margarine in a frying pan (for maximum evaporation!) and mix the flour into the mix, allowing the paste to cook for a few minutes to remove that raw-floury taste and texture. Lower the heat.
Very slowly add a cup of the soymilk (or milk, I know you don't all love soymilk like I do!) whilst constantly stirring, so that it becomes incorporated completely without creating lumps. Using a whisk is a good idea to remove lumps.
As the sauce thickens, add more soymilk to thin it. Adjust the heat as necessary - I have an electric hotplate, so I turn the heat up to medium and simply remove the pan from the heat when it's thickening too quickly - that way I can add more liquid before it becomes a thick paste.
How much liquid you need depends on how thick you want your sauce to be. At a certain point the roux (flour mix) will reach saturation point at the sauce will stop thickening. Once this happens, simply add liquid to reach your desired texture, and serve immediately.
To use this over pasta, I recommend a few tablespoons of finely chopped, fresh parsley and a generous grind of each salt and pepper.