The main thing is to toss the veggies in olive oil to be sure they are all covered with a thin film. Could mix a little balsamic vinegar, salt and pepper.

For example these are some of my favorite combinations.

For green veggies, I toss with olive oil, S&P, and might drizzle some balsamic reduction over top when serving.

I do summer veggies (eggplant, zuchinni, yellow squash, red onion, red pepper) with 3 T. Red wine vinegar, 2 tsp. olive oil, & 1/4 cup fresh basil, chopped

Potatoes, Brussels sprouts and bacon gets 1 T. each olive oil and prepared Dijon mustard, salt & pepper

Acorn squash, shallots, rosemary gets 3T olive oil, 1/4 cup balsamic vinegar, salt & pepper

But I have to say, I'm really having trouble getting my head wrapped around a combination of beets, tomatoes, and squash....