Preheat your oven to 400°F (200°C). Line a large baking sheet with parchment paper. In a bowl, toss the sweet potato cubes with 1 tablespoon olive oil, 1/4 teaspoon salt, and a pinch of pepper. Spread in a single layer on one side of the baking sheet. In the same bowl, toss broccoli florets with remaining 1 tablespoon olive oil, 1/4 teaspoon salt, and pepper. Place on the other side of the sheet.
Roast for 25-30 minutes, flipping halfway through, until sweet potatoes are tender and lightly caramelized, and broccoli is charred at the edges. Remove from oven and let cool slightly.
While vegetables roast, whisk together peanut butter, soy sauce, maple syrup, rice vinegar, sesame oil, garlic, and ginger in a small bowl. Add warm water 1 tablespoon at a time until smooth and drizzle-able. Taste and adjust salt or sweetness as desired.
Divide warm quinoa or rice among 4 bowls. Top with roasted sweet potatoes and broccoli. Add sliced avocado on the side. Drizzle generously with peanut sauce. Garnish with fresh cilantro and a lime wedge.
Serve immediately, squeezing lime juice over the bowl just before eating. Encourage diners to mix everything together for the best flavor.