The healthy white sauce is made by roasting whole wheat flour in olive oil along with low-fat milk and bottle gourd puree. Here plain flour is replaced with whole wheat flour, butter is replaced with oil, full-fat milk with low-fat milk. The bottle gourd puree gives it a thick creamy texture without compromising the taste.
Wash and chop bottle gourd (doodhi/lauki) into pieces. Pressure cook it for 3-4 whistles with a half cup of water. (If you do not have bottle gourd you can also use cauliflower).
Cool and drain the cooked bottle gourd. Make a smooth paste of it in the mixer. (the drained water can be used to knead flour, or making dal and soup).
Heat olive oil in a pan.
Add the whole wheat flour.
Saute till the wheat flour become golden and releases the aroma.
Add gradually milk stirring continuously so that no lumps are formed.
Add the pureed bottle gourd and mix well. If possible use a hand whisk to mix as it prevents forming lumps.
Mix well and simmer on medium heat till sauce thickens.
Add oregano, black pepper powder, and salt and mix well. (you can keep it plain or add spices like mixed herbs, red chili flakes, nutmeg, garlic powder.)
Simmer for two more minutes. The white sauce is ready to use.