Cook the black rice according to package instructions (or see post for easy cooking steps). Set aside to cool afterwards. Recommended step: soak the rice for 30 minutes before cooking. While the rice soaks, you can do all the prep for the salad.
While the rice is cooking, get all the salad ingredients ready: finely dice the red onion, cut the grape tomatoes in half and roughly chop up the fresh spinach. Crumble the feta cheese, rinse and drain the bean salad.
In a large bowl, add the diced red onion, halved grape tomatoes, chopped spinach, crumbled feta cheese and mixed bean salad.
In a small mason jar, add all the dressing ingredients, secure the lid and give the jar a good shake.
Pour dressing over the salad and toss everything together to combine.
Enjoy right away or store in the fridge for up to 3 days.