1. In a medium bowl, mix the parsley, black olives, olive oil, anchovies, garlic, lemon juice and thyme. Season the dressing with salt and pepper.
2. In a small pot of boiling salted water, blanch the snow peas for 1 minute, or until they are bright green and just tender. Drain the snow peas and refresh them under cold water, then pat dry. Slice the snow peas lengthwise into 1/4-inch strips and toss them with 1 tablespoon of the olive dressing.
3. In a medium bowl, lightly break up the drained tuna with a fork. Add 6 tablespoons of the olive dressing and toss gently.
4. Spread the cut sides of the rolls or baguette pieces with the remaining olive dressing. On the bottom halves of the rolls or baguette pieces, arrange the snow peas, followed by the red onion slices, the tomatoes, tuna and sliced eggs. Close the tuna sandwiches and serve.
Make Ahead: The tuna sandwiches can be kept at room temperature for up to 3 hours.