yes you do for a proper cheese sauce ric, you can't just melt the cheese into the milk or cream- what are you trying to avoid?
does it have to be lasagna?
this also works well if not
440g Mince (beef, lamb, pork or veal)
1 tsp dried Italian herb mixture/just oregano
1 small chopped and lightly fried Onion
20-30g Breadcrumbs
2 Eggs
Salt and Pepper
180g Sour Cream
20g grated Parmesan
Mix mince with herbs, onion, breadcrumbs and 1 egg, season with salt and pepper.
Grease an ovenproof dish and fill with the mixture.
Mix the sour cream with the other egg and parmesan and spread on top of the meat mix. Cook on 200ºC oven,20-25 minutes. Take it out and rest for 10 minutes. Serve with fresh green salad and crispy warm baguette.
That makes a cheat bechamel topping, but it wouldn't work if you used it in layers