Heat 2 teaspoons of the oil in a medium skillet. Add the onion and cook until translucent, about 3 minutes. Add the garlic and cumin and cook for 30 seconds more. Add the beans, broth and 1/2 teaspoon of salt and cook until warmed through, about 2 minutes. Transfer the bean mixture to the small bowl of a food processor and process until smooth.
Put the lettuce, cilantro, the remaining 2 teaspoons of oil, lime juice, a pinch of salt and a few turns of pepper in a medium bowl and toss to coat.
Wrap the tortillas in paper towel and heat in the microwave for 30 seconds.
To build the burrito, spread 1/3 cup of the bean puree in the center of a warm tortilla. Sprinkle with about 2 teaspoons of jalapeno. Top with 1/2 cup of shredded chicken, then 1/2 cup of the lettuce mixture and 2 slices of avocado. Wrap into a burrito. Repeat with the remaining tortillas.
Serve with the salsa and yogurt alongside.
Excellent source of: Fiber, Niacin, Protein, Thiamin, Vitamin A, Vitamin C, Vitamin K