Wash potatoes, peel, if desired (mine were organic so I didn't bother) chop into large pieces, and cook until fork-tender in a large pot of boiling salted water. Then drain and chop into smaller cubes.
In the meantime, cook bacon using your method of choice (I like the microwave for smaller amounts of bacon - it's very hands off*), rinse and chop a handful of cilantro, dice 1/2 a red pepper, and cook (and drain very well) 2 cups of frozen corn.
Mix 1 cup plain yogurt, 1/2 cup mayo and 3 tbsp ranch dressing mix** - see the link to the recipe below. Add 1 teaspoon of salt, juice of 1/2 a lime (about 2 tablespoons) and 1/4 teaspoon of chipotle powder (or smoked paprika). Taste to see how spicy it is. If you'd like it stronger, keep adding more spice, a 1/4 teaspoon at a time. I ended up using 1/2 teaspoon in total.
(Like I said above, I used chipotle powder for this recipe, which can vary in heat depending on the brand you use and how old it is. It's best to start with a little and add to it. Or, if you don't want any spicy heat, use smoked paprika instead. It will give you that smoky southwest flavour without any risk of a burning mouth.)
Toss everything together and chill for at least 1/2 hour to let the flavours blend.
Enjoy! :)