Bring a large pan of water to the boil. Once boiling, place the spaghetti in the pan.
Chop the rainbow chard and asparagus into 2cm pieces. Once the spaghetti has been cooking for 4 minutes, add all the veg in with the pasta. Cook for a further 5 minutes.
Set aside 3 tbsp of the water from the spaghetti and vegetables. Drain and leave in the colander.
Spray the saucepan with some low calorie cooking spray and cook the crushed garlic on a moderate heat for a minute or two, being careful not to burn it.
Turn off the heat and remove the pan from the hob. Return the spaghetti and vegetables to the saucepan with the held back cooking water and stir in the quark and lemon juice. Season well with salt and pepper. Don't try to do this on the heat as the quark will split!
Serve immediately (with a sprinkle of parmesan if you like!)