The Tale of Bitter Onions!

Okay so we decided to cook after a long time. Recipe - potatoes, cauliflower and lots of onions. Being lazy as usual we decided to grind the onions in the blender. After half on hour of hardwork the result was an awfully bitter concoction of what was intended to be Indian dish. Damn it was bitter, more bitter than anything I've ever had. My roommate quickly jumped to the conclusion that it was poisoned. A quick google search revealed that the overcooking onions can make them bitter but it was not well known and not something cooking sites warn you about. Many a times I burn onions but they never turn bitter (By now my roommate is sure he has tasted poison!). Next morning my roommate has a sore eye and the first thing he does after waking up is throw the dish, holding his breath all the time of course. Some how I myself could not sleep last night, and still have that awful taste lingering in my taste buds. Sure I will be more careful with onions for a while. Back to maggi and pasta!!