Add spinach, cilantro, jalapeño, garlic, lime juice and salt into a food processor. Pulse until a chunky paste forms.
Add quinoa and green paste into a small sauce pan. Cover with water and stir to combine. Bring to a boil, then cover and reduce to simmer. Simmer for 15 - 20 minutes until the water is absorbed and quinoa is fluffy. Remove lid and set aside for 5 minutes.
While quinoa is cooling, add the black beans, corn and tomatoes into a small bowl. Stir together then season with spices, lime juice and salt. Taste and adjust seasonings as necessary.
Before serving, taste the quinoa and adjust the salt if needed, then serve warm with the black bean salad and diced avocado. Garnish with cilantro and hot sauce if desired.