Place baby spinach in a large bowl, and set aside. Chop onions and rinse and drain beans.
In a medium sized bowl, pour in vinegar. Using a whisk, slowly drizzle in oil, whisking constantly, until combined. Season with Adobo. Toss in low sodium pinto beans and onions. Mix well.
Pour mixture over baby spinach. Toss well to coat. Divide salad evenly among serving bowls and enjoy.
Optional: Top with GOYA® Adobo Light All-Purpose seasoning or chili pepper flakes to taste