Roasted Savory Mushrooms & Onions

Birthday dinner! Ok, so while I was buying that beef tenderloin, the butcher convinced me to go to the veggie section and have a sample of one of the veggie sides. He also told me that Caesar salad isn't a vegetable. 

Anyways, I went and bought 2 packages of prepackaged veggies. The recipe below is from the Wegman's website. I was going to buy the finishing sauce, however it contains gluten and this was to be a gluten free meal! I took a picture of the bottle and made up my own recipe without the soy sauce!
 
Birthday Menu: Beef Tenderloin, Swedish baked potatoes, roasted onions and mushrooms, and a Gluten Freeblueberry cobbler!


Gluten Free Copycat of Wegman's Finishing Sauce (more or less)
2 tbsp Butter, melted
2 tbsp Balsamic Vinegar
1 tbsp Tomato Sauce (I didn't have tomato paste)
1 tsp Sugar
1/2 tsp Ginger
1/2 tsp Onion Powder
1/4 tsp Salt

Combine all the ingredients and then adjust any flavors for your personal taste!

Savory Mushrooms and Onions
2 pkgs(10 oz each) Baby Bella Mushrooms, halved
1 pkg(6 oz) Cipolline Onions
1 pkg(6 oz) Pearl Onions
Salt and pepper
1/4 cup Wegmans Basting Oil
2 Tbsp Wegmans Savory Finishing Sauce
 

Preheat oven to 450 degrees. Toss mushrooms and onions with basting oil in large bowl; arrange in single layer on baking sheet. Season with salt and pepper. Roast on center rack of oven 15 min.
Reduce heat to 350 degrees; cook 25-30 min, until vegetables are caramelized. Spoon vegetables into serving dish; drizzle with sauce.