In a large skillet, heat oil over medium-high heat. Add the yellow onion and cook, stirring, until just beginning to brown, about 6 minutes. Add the garlic and cook for 1 minute. Add the tomato mixture, broth and salt and bring to a boil. Reduce heat to low and simmer for 10 to 15 minutes, stirring occasionally, until slightly thickened.
Preheat oven to 400 degrees. Just before assembling the casserole, add the chips to the skillet with sauce and toss to coat.
Spread 1/3 of the chip mixture in an even layer across the bottom of a 2-quart baking dish. Top with 3/4 cup of cheese, half of the chicken and half of the beans. Repeat layering process one more time, using another 1/3 of the chips, 3/4 cup of sauce, 3/4 cup cheese and remaining half of chicken and beans. Top with the remaining 1/3 chip mixture and 1/2 cup cheese.
Bake until cheese is melted and casserole is heated through, about 20 to 25 minutes. Remove from oven and let stand for 10 minutes. Garnish with sour cream, avocado, cilantro and red onion. Serve with lime wedges on the side.