Preheat oven to 450 with a baking sheet inside. Toss potatoes with 2 Tbsp. oil and 2 Tbsp. taco seasoning and season with salt and pepper. Transfer potatoes to hot baking sheet and roast til for tender, 20 minutes.
Drain jalapenos, reserving 1/4 cup juice. Pour jalapeno juice over hot potatoes and chill til cool. Mix sour cream, salsa Verde, and 2 Tbsp. taco seasoning.
Mash avocados with garlic, then season with salt. Layer potatoes, avocado mixture, jalapenos, and sour cream mixture in large glass bowl. cover and chill til ready to serve
Whisk together lime juice, remaining 1 Tbsp. oil and taco seasoning; toss with lettuce, cilantro, scallions and olives. Top salad with lettuce mixture, pico de gallo and corn chips.