Preheat oven to 415º.
Spray sweet potatoes with olive oil and wrap in foil. Place on a baking sheet and roast for 50 minutes or until fork tender.
While the sweet potatoes are roasting, prepare the onion and red pepper as instructed above. Heat oil in a large skillet over medium-high heat. Add onions and pepper and sauté for 5-7 minutes.
Add black beans, quinoa, sea salt, and more olive oil if necessary. Continue to heat for 3-5 more minutes.
When the sweet potatoes are done, slice them in half and fill with the stuffing.
Top with fresh cilantro and a squeeze of lime.