In a large mixing bowl combine all marinade ingredients and whisk to combine. Add steak to a large zip top bag and add half the marinade. You will need to marinate this in the fridge overnight. Reserve the remaining marinade for the shrimp which you will marinate 30 minutes prior to grilling.
Once ready to grill, remove both the shrimp and the steak from the marinade and grill to your liking. Once the steak has had some time to rest, cut it into thin strips.
Creamy lime avocado dressing:
Combine all ingredients to a food processor and process until smooth and creamy. Add a bit more water if you prefer your dressing a bit thiner.
Preheat the oven to 425°. Boil potatoes for six minutes and then drain and run them under cold water. Add the potatoes to a baking sheet lined with parchment paper and sprayed with cooking spray. Take the back of a cast iron pan and smash the potatoes. Add potatoes to the oven and bake for 35 minutes. You want them crispy.
Salad bar Assembly:
Using a large cutting board or serving platter arrange shrimp and steak next to each other. Dollop sour cream and spread it around in one of the corners and arrange the smashed potatoes over it. Add a pile of the chopped romaine and drizzle with dressing. Place grilled veg all over the serving platter covering any empty spots. Add the remaining dressing to a bowl for your guests to top their salad.