Bring water to a boil in a saucepan over medium heat and add pearl onions.

Boil onions for 3 minutes, then drain and rinse well.

Snip off ends of onions and slip off the peels.

Heat olive oil in a large skillet over medium-high heat and add butter.

When the butter melts, lower heat to medium and add shiitake mushrooms, cooking until they brown around the edges.

Add onions to the pan and cook until light brown.

Push vegetables to the edge of the pan and pour in sherry wine vinegar and rum.

Cook, scraping the bottom of the skillet, until the mixture comes to a boil and reduces to a glaze.

Season with salt and pepper.

Remove from heat and let cool slightly.

To serve on individual plates: cover salad plates with mixed greens (3/4 - 1 cup per serving), spoon mushroom/onion mixture over greens, and top with 1/2 ounce of crumbled goat cheese.

To serve in a salad bowl: put greens in bowl, top with mushroom/onion mixture.

Toss gently.

Add goat cheese and toss again.