Whisk together the vinegar, mustard, 1 tsp. dill and lemon zest. Slowly add the oils while continuously whisking. Season to taste with salt and pepper.
For the salad:
Cut the goat cheese into 6 slices and lay flat in one layer on a shallow plate. Combine the extra-virgin olive oil and 1 Tbsp. dill and pour over the goat cheese; marinate for 2 hours.
Wash the radicchio and romaine leaves and dry thoroughly. Pour vinaigrette in large bowl. (Use only as much vinaigrette as you like and reserve the rest.) Tear the greens into small pieces and add to bowl and toss lightly to coat.
Divide the greens between 2 salad plates.
Preheat a 10-in. nonstick omelette pan on medium heat until the rim is hot to the touch.
Add goat cheese disks to the pan and heat for 1 minute, turn gently and heat for another minute.
Remove the cheese disks from the pan and place 3 pieces around each salad plate and serve immediately.