Preheat your oven to 400°F (200°C).
Toss the cubed sweet potatoes with olive oil, cumin, smoked paprika, salt, and pepper. Spread on a baking sheet and roast for 25–30 minutes, or until tender.
While the sweet potatoes roast, prepare the Swiss chard pesto by combining Swiss chard, toasted nuts, garlic, lemon juice, and a pinch of salt in a food processor. Blend until smooth.
In a skillet over medium heat, add a tablespoon of olive oil and sauté the rinsed black beans for 3–4 minutes. Season with salt and pepper.
Once the sweet potatoes are roasted, mix them with the black beans in the skillet. Stir to combine, adjusting seasoning as needed.
Heat a large skillet over medium heat and add a tortilla, followed by a generous amount of the sweet potato mixture and a sprinkle of cheese. Top with another tortilla.
Cook for about 3-4 minutes on each side, or until the tortillas are golden brown and the cheese has melted. Repeat with remaining tortillas and filling.
Slice the quesadillas into wedges and serve hot, topped with Swiss chard pesto.