Is it ok to eat a huge salad as long as you use a healthy alternative to dressing?

I just ate a big salad but used Tuna fish instead of dressing. The tuna is the one in water and not the oil and was not fattening. Also had a boiled egg but no cheese, croutons or bacos ect...

Is this a good meal to have 2-3 times a day when tryinjg to lose weight?