I won't image just cauliflower and béchamel sauce with a little smoke cheddar will create such a wonderful flavor combination. But just as simple as only one veggie and white sauce made a wonderful lasagna that beyond my knowledge. I made this lasagna from scratch. The go-to filling-butternut squash was out of stock in my house but there happened to have a head of cauliflower waiting to be used. So I cooked the cauliflower and mashed them, layed the filling and cheese sauce on each pasta sheet. The very top was coverd with extra smoke cheddar. I loved this dish so much that will sure to make it again.