Cook brown rice according to package instructions if you don't already have cooked brown rice on hand
If doing stove top: once rice is made, stir in cinnnamon, black beans and deli mustard (if using) until combined and heated through
Mix in walnuts and top with shredded cheese (if using)
If using microwave: make/heat rice. Add beans, cinnamon, mustard (if using) and heat for ~1.30 minutes. Stir in walnuts and top with cheese (if using) and microwave ~30 seconds more to melt cheese
Divide, eat and enjoy!