Pour vinegar and lime juice in a small bowl.
Add oregano, salt, sugar, and black pepper.
Pour the oils into a small stream, whisking to emulsify. (Can be made a day or two ahead, emulsify right before using)
Mix together hearts of palm, green beans, onion, and tomatoes with the vinaigrette.
Sprinkle with pine nuts.
This can be served over greens also.