Absolutely. Obviously not all dishes work well with substituting steaming or roasting for cooking them in their traditional manner, but there are many great dishes that are steamed or roasted.
I regularly order a steamed combo meal at my local Chinese restaurant. It has no added MSG, oils, fats, or salt. - it's all steamed and it comes out great. I get steamed chicken or shrimp with mixed fresh vegetables over steamed rice. To top it all off, they make their own fat free, low sodium garlic sauce to go over it all and keep everything moist. I think it's just a mixture of chicken stock, garlic and corn starch if I had to guess. The nice thing is that you can really taste the sweetness of the vegetables and the flavors of the shrimp or chicken when you order it like this. I think they also "velvet" the chicken with a little corn starch before they steam it too, to give it a smooth texture.
As for roasting, roasted chicken is an obvious and east one - especially if you discard the skin after roasting it. But even Pizza can be made more healthy, as opposed to cooking in a deep pan swimming with shortening and drowned in greasy cheeses - just dust the cooking surface with corn meal instead and cook it on that instead of a greased surface. Also you can swap out the heavy handed mozzarella cheese for a dusting of Romano instead, and add some toppings like sweet peppers - which will become even sweeter during the cooking process.