Skirt Steak Tacos With Guacamole And Lime Crema

4 ripe avocados, halved pitted and mashed 1 cup chopped roma tomatoes (3 medium) 1 cup coarsely chopped fresh cilantro ⅓ cup finely chopped red onion (1 small) ¼ cup lime juice 1 teaspoon salt

Lime Crema

1 8 ounce carton dairy sour cream 1 teaspoon finely shredded lime zest 3 tablespoon lime juice