My creamy cheese sauce is super simple. It takes about 10 minutes. I lightly saute a little chopped garlic and/or herbs in some olive oil or butter. Then I reduce heat to medium or medium low and add heavy cream. Since you're using an electric stove, either pull the pan off the burner and reduce heat, or use a second burner preheated to medium.
Then I simmer it a little, stirring frequently - small bubbles around the edge of the pan are good. A rolling boil is not. Anyway, next I add whichever grated cheese I have and like - for example, a mix of padano and parmesan is good. For a stovetop mac-n-cheese flavor, maybe cheddar or a mix of cheddar and parmesan would be good. Gruyere or gouda are great. I finish with salt and white pepper as needed. With cheddar cheese, a dash of paprika is good.
You'll notice I use no flour in mine - I like it pourable, and the cheese and simmered cream give it enough thickness to cling to pasta or veggies. If you want to thicken it, use a blonde roux - flour cooked in butter until it is beige. Add it to your sauce a little at a time until you get the desired thickness. If it's still white and smells like flour instead of like toast, your roux is undercooked. That's what makes flour-thickened sauces taste pasty.
Good luck!
P.S. - I just remembered seeing a "Good Eats" episode on which Alton Brown makes a homemade stovetop mac-n-cheese. I'll bet his recipe is on foodtv.com.