Melt butter for sauce. Add milk and water. Heat through. Add maizena (corn flour) and thicken into pouring sauce. Whisk continuously for a smooth sauce. Add liquidized pepper and heat through. Check seasoning.
Boil pasta with salt and oil till al-dente. Drain and toss in sauce.
Saute julienned pepper and mushrooms with salt and garlic till veg is just tender. Add to pasta.
Add chicken and cheese to pasta and mix altogether. Garnish with oregano and poppy seeds and serve.
INFO & TIPS
You may use fresh cream instead of making sauce. Just add peppers and fresh cream to chicken and mushrooms. Allow to thicken. Add pasta and serve.