Meanwhile, roughly chop the spinach. Place in a large mixing bowl.
Mince garlic and add to spinach. Halve/quarter cherry tomatoes, slice green onions, and dice avocado.
When quinoa is done cooking, immediately add it to the large bowl with spinach & garlic. Toss well to combine. The heat from the quinoa will lightly wilt the spinach and mellow the garlic.
Add the tomatoes, green onions, red wine vinegar, and salt to taste. Stir to combine. Add the avocado and lightly toss.
Serve immediately or refrigerate to let flavors blend/intensify.
*To cook 1 cup quinoa: in a small saucepan, boil 1 1/2 cups water (or vegetable broth for more flavor). Once boiling, add rinsed quinoa, reduce heat, cover, and simmer for about 15-20 minutes or until liquid has absorbed. The dressing & flavors are highly customizable. You can use red wine vinegar alone, or add fresh lemon juice, Dijon mustard, dried or fresh herbs, etc. for a bit more flavor.