Meatloaf Sandwiches without tabasco

2 teaspoons olive oil 1 red onion , chopped 1 zucchini , shredded 3 carrots , shredded 1 yellow bell pepper , chopped 1 celery , chopped 8 mushrooms , chopped[...]

4 slices sourdough bread, toasted grainy mustard (Inglehoffer from Oregon is recommended!) baby spinach leaves or loose leaf lettuce 2 -4 slices leftover[...]