Heat olive oil in a large skillet over medium high heat.
Chop onion and add to hot oil; sauté 5-7 minutes until starting to brown.
Add corn kernels and sauté another 2 minutes or until tender.
Add beans, taco seasoning, and water. Sauté another minute until warmed through, then remove from heat and allow to cool.
Place lettuce in a large serving bowl. Add bean mixture and crushed tortilla chips, then top with sliced avocado, tomatoes, cheese, cilantro, and dressing.
Garnish with lime wedges if desired, and serve peaches on the side.