Ensaladilla rusa (no idea why we call it "Russian salad")

Ensaladilla rusa (no idea why we call it "Russian salad")
From: Nava

Compulsory veggies: small potatoes, carrots, green beans. Optional: peas.
Other optional things: green boneless olives, tuna (1), hard-boiled egg.
Mayo, garlic mayo, alliolli or pink sauce (mayo with a dash of tomato).

1: at home we normally use tuna preserved in vinegar, but I don't normally find that abroad. The kind canned with just water works too. You can sharpen up the "plain" tuna by opening the can a couple days before and transferring the contents to a mason jar or similar recipient along with a generous amount of white vinegar.

Amounts:
Potatoes: about 1/3 what you'd use as a main dish. Less than 1/3 for beans, less even for carrots.
Peas, tuna, olives, egg: a sprinkling of each.

The veggies are cooked separatedly in salt and water (as they all have different times to be "just cooked enough," you don't want to overcook them), cut into crouton-sized pieces and mixed.
The sauce, chopped olives, tuna and cube-chopped egg can be mixed in as well, but I prefer to put them on the side so each person can use only those items he likes.