Bring large pot filled with water to boil over high heat. Add potatoes and 1 tbsp. Adobo. Reduce heat to medium. Cook potatoes until fork-tender, about 15 minutes. Drain.
Meanwhile, add vinegar and onions to large mixing bowl. Transfer hot, cooked potatoes to bowl, stirring to coat. Set aside until potatoes are cool and have absorbed vinegar.
Add carrots, beets (if using), peas, mayonnaise and eggs to potatoes. Using large spoon, gently stir to combine. Season with Adobo. Serve chilled or at room temperature