Add quinoa and water or stock to a medium pot and bring it to a boil over high heat. Cover, reduce heat to low, and simmer for 10-12 minutes until the quinoa absorbs all the water and is fully cooked.
Remove from heat and let it sit for 5 minutes. Transfer to a large bowl and fluff with a fork. Lightly cover with plastic wrap and refrigerate for 1 hour to cool.
While the quinoa is cooling, make the dressing. Add all ingredients to a small bowl or mason jar, and whisk or shake together to combine. Cover and refrigerate until ready to serve.
When the quinoa has cooled, add the black beans, yellow corn, grape tomatoes, red onion, and crumbled cotija cheese to the bowl.
Pour in the dressing and toss to combine. Taste and season with more salt, if necessary.
Serve immediately or cover and refrigerate until ready to serve.
Cheese substitution: If you can’t find cotija cheese, you can use crumbled feta instead. Or leave it out completely to make this vegan friendly.
Storage: This salad can be stored in the refrigerator for up to 1 week.
It’s important that the quinoa is completely cool prior to assembly. This ensures the dressing coats the outside of the grain instead of being absorbed and the veggies don’t cook when combined with the heat.
If you are making this salad ahead of time, do not toss in the tomatoes until it’s time to serve. The fresh tomatoes can release their natural juices and become soggy if they sit too long.