Fennel gratin with lemon and romano

Ingredients

• 5 Tbs. olive oil
• 1 lg. onion
• 3 lg. garlic cloves
• 5 fennel bulbs
• 1/4 c. chicken broth
• 1/4 c. dry sherry
• 2 Tbs. parsley
• 1 Tbs fresh thyme
• 1-1/2 tsp salt
• 1/2 tsp. pepper
• 3 Tbs. butter
• 3/4 c. panko breadcrumbs
• 1 c. Pecorino Romano cheese
• 1 Tbs. parsley
• 1-1/2 tsp. lemon peel