1. Wash and cut mushrooms into quarters. Chop fennel bulb.
2. Heat olive oil in a large heavy frying pan large enough to hold all ingredients. Add mushrooms, fennel, garlic, thyme, and sage and saute, stirring a few times, until the mushrooms are softened and starting to brown. This will take about 8 minutes.
3. Add 1/4 cup chicken broth and let simmer covered for 5-6 minutes, until mushrooms have shrunk somewhat and released their juice.
4. While mushrooms cook drain the beans into a colander and rinse with cold water until no more foam appears. Add drained beans, tomatoes and simmer 10 minutes more. After 10 minutes the stew should be slightly thickened and flavors should be well-blended. Season to taste with salt and fresh ground black pepper.