Cook the quinoa according to package directions.* Meanwhile, roughly chop the spinach. Place in a large bowl.
Mince garlic, and add to spinach. Slice the green onions, halve the cherry tomatoes, and dice the avocado.
When quinoa is done cooking, add it to the large bowl with spinach and toss. (The heat from the quinoa will lightly wilt the spinach and mellow the garlic.)
Add the green onions, tomatoes, red wine vinegar, and salt. Stir to combine. Add the avocado and lightly toss.