Gluten free, meat free please!
Roasted vegetables such as bell peppers, tomatoes, onions, are good.
Greens (chard, spinach, kale collards, etc.) sauteed in olive oil with garlic, onion and red pepper flakes and cooked until tender.
Cruciferous vegetables (brocolli, brocolli rabe, cabbage) treated the same way.
Sauteed mushrooms or mushroom ragu.
Throw a poached egg on any of the above suggestions, too, if you want to kick in some protein.
Rich sauces like gorgonzola also work (though it's heavy of course, especially for summer)
These are the two options offered for soft polenta with poached egg, for breakfast, at my favorite cafe:
1. pulled pork, red pepper sauce
2. bacon & blue cheese with a drizzle of maple (I prefer this one)
I always enjoyed sauteed mushrooms and greens (spinach, kale) with smokey tomato cheese sauce. Start with a bechamel and stir in some tomato paste and grated, smoked gouda, pepper and thyme. I have also stirred smoked blue cheese into soft polenta and topped with a pile of gently cooked vegetables and toasted pecans.
I like roasted veggies, mushroom ragu and pesto with lots of parm. I also like the greens like "sfmiller" except I also add a handful of currants and a splash of sherry vinegar to get the sweet and sour taste.
My very favorite is sauteed mushrooms and a thick meatless tomato sauce.
Oops...just saw you were wanting gluten- and meat-free. Guess my gravy enthusiasm wouldn't be too funny. I have served ratatouille over polenta, which is delish and stretches the ratatouille further.
Very thick tomato sauce--preferably roasted. Pesto is also very nice. Mushroom ragout is a favorite around here.