Mix the vinegar and mustard; season to taste with salt and pepper.
Slowly whisk in oils; reserve.
To assemble salad, cut each avocado half into 3 slices; fan around the outside perimeter of the plate.
Place the orange segments between the avocado slices; sprinkle both with salt and pepper.
Toss the frisee with 1/2 tablespoon of vinaigrette; place in the center of the plate.
Garnish with Roma tomato and toasted pecans; drizzle with remaining vinaigrette.