Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Clean and dry the mushroom caps, or slice mini eggplants in half, yielding six eggplant “boats.”

Pour one cup marinara sauce on the bottom of a 9×13-inch baking pan. Arrange the mushrooms or eggplant in the marinara sauce. Drizzle with olive oil, kosher salt, and pepper. Cover pan with foil and bake for 30 minutes.

Meanwhile, place the raw quinoa and “beef” broth in a small saucepan and bring to a boil, then lower to a simmer for 15 minutes. Remove from heat and do not lift cover. 

Allow to sit another 15 minutes to assure all water is absorbed. Add in remaining marinara sauce.

Remove mushrooms or eggplants from oven. Spoon a tablespoon of the quinoa mixture into each mushroom or eggplant half. Top with a generous sprinkling of shredded Muenster cheese. Bake for an additional 10 minutes, uncovered.