These trim, elegant sandwiches make a perfect lunch or hors d’oeuvre. They aren’t hard to prepare, but there are a couple of things to keep in mind as you assemble them: shred the lettuce and slice the tomatoes and mushrooms very thin; doing so will help the sandwiches hold together and make them easy to nibble.
1. Prepare stove-top smoker with wood chips.
2. Whisk together oil and lemon juice in small bowl; season with salt and pepper, if desired. Brush both sides of mushroom caps with half of oil mixture, and set on smoker rack. Smoke 25 minutes, or until mushrooms are tender and light brown. Uncover smoker, and cool mushrooms.
3. Toast bread slices. Thinly slice mushroom caps on bias (cut on steep diagonal to get more surface area). Arrange mushroom slices in even layer over 2 toast slices. Add a layer of sliced tomato and another slice of toast. Toss together lettuce, goat cheese, and remaining oil mixture in small bowl. Divide lettuce mixture among sandwiches, and top with remaining toast slices. Press down lightly but firmly or weight with dinner plate for a few minutes to help keep fillings in place after slicing. Cut sandwiches into quarters.