Preheat oven to 300°F. Line a rimmed baking sheet with parchment paper.
Using a sharp knife, cut each tomato in half lengthwise. Arrange cut tomatoes on prepared baking sheet. Spray tomatoes lightly with olive oil or drizzle with olive oil. Sprinkle or brush on white balsamic vinegar and season with salt and pepper.
1 can (28 ounces) whole peeled tomatoes, 1 teaspoon olive oil, 1 tablespoon white balsamic vinegar, ¼ teaspoon kosher salt, ¼ teaspoon ground black pepper
Place in preheated oven for 1 hour 10 minutes to 1 hour 20 minutes, or until soft and golden brown around the edges.
For mushrooms:
In a large frying pan, heat 1 teaspoon olive oil over medium-high heat. Add mushrooms and season with salt and pepper. Sauté until golden brown.
1 teaspoon olive oil, 8 ounces fresh mushrooms, cleaned and sliced, ¼ teaspoon kosher salt, ¼ teaspoon ground black pepper
To assemble each bowl:
Add ½ cup quinoa to bowl, followed by ½ cup to 1 cup baby spinach, ¼ cup ricotta, 4 tomato halves, and a spoonful of mushrooms. Drizzle with balsamic glaze and serve. Note: If some of your ingredients are chilled, microwave them briefly to warm them up.