I like to steam a bunch of vegetables and add the sauce on top. The sauce will prvide the fat to get all the nutrients you need if you add olive oil to it or add undrained ground beef or pork to it (I wouldn't add both the undrained meat AND the olive oil or the sauce constancy gets a bit messed up).
A good combination of veggies I have used is:
Okra (if in season)
Various bell peppers of all colors
A spicy pepper or two of your choice
That mix provides a good mix of nutrients and flavors. Just make sure you steam the leafy greens only for a minute or two since the hot pasta sauce will continue to cook the greens.
Or you could sauté some eggplant in butter or coconut oil and toss the pasta sauce on top of the slab.