Bring a medium saucepan of salted water to boil over medium-high heat, then cook green beans until crisp-tender, 1 minute.

Remove with a slotted spoon and run under cold water, then transfer beans to a paper-towel lined plate to dry.

Return water to a boil and gently lower in eggs with a slotted spoon.

Cook eggs 9, then drain and run under cold water.

Peel eggs and quarter lengthwise.

Whisk oil, mustard, vinegar, and salt and pepper in a large bowl.

Add romaine and toss to combine.

Divide between serving bowls and top with tuna, tomatoes, olives, green beans, and eggs, dividing evenly.