Work on a large cutting board or work surface. Divide the ingredients between the two sandwiches to build the sandwiches.

On one half of each sandwich arrange the avocado slices, about 4 or 5 per sandwich. Then sprinkle over the shredded cheese, carefully layer on the spinach leaves and sprinkle on a bit of vinaigrette. Evenly cover the remaining slices of bread with the goat's cheese. Use a knife to gently press the crumbled cheese into the bread. Carefully place the bread cheese side down over the spinach side. Tuck any runaway ingredients back into the sandwich.

On the stove top: Heat a grill pan or wide flat skillet to medium heat. Once the pan is warm, coat the bottom of the pan with a few sprays of olive oil or non-stick spray. Gently place one, or if space allows, both sandwiches in the warm pan. If possible set a pot lid or sauce pan on the sandwiches to press them gently. Pressing the sandwiches helps them get more evenly toasted. Covering the sandwiches also helps them warm through the centers more evenly. Check frequently to prevent burning. After about 5 minutes they should be toasted to medium brown and ready to flip.

Spray the not yet toasted top of each sandwich with a few sprays of oil or non-stick spray. Use a wide pancake flipper to turn the sandwiches over in the pan. At this point the spinach should be partly wilted and the cheese should have begun to melt so the sandwich should hold to together while you flip them. Replace the lid or pan on the sandwiches and toast for another 3 - 4 minutes. Continue to check the progress frequently to avoid burning the bread then serve hot.