1 4-x-16-inch loaf French bread 2 Tbsp. olive oil 8-oz. sweet or hot Italian sausage 1 c. yellow onion, sliced 4 c. (6-oz.) fresh baby spinach 1 c. grape tomatoes, halved 1/2 tsp. red chile flakes, optional 1 c. (about 8-oz.) Wisconsin Fresh Mozzarella, cubed 1/2 c. (2-oz.) Wisconsin Provolone Cheese or Parmesan, shredded 6 Tbsp. pizza or marinara sauce
Preheat oven to 400° F. Slice the top quarter from bread. (Reserve slice for another use.) Remove bread from bottom, hollowing loaf and leaving 1/2- to 3/4-inch border with crust. Place bread on baking sheet. Brush inside with olive oil and bake 5 minutes, or until edges are golden and bread is slightly dry. Remove casing from sausage. Heat large skillet, adding a little oil if sausage is very lean, over medium and add sausage, crumbling, and cook until almost browned. Add onions. Cook 4 minutes, until onions soften. Add spinach, in batches if necessary, and cook 2-3 minutes, until spinach is wilted. Remove from heat. Add tomatoes, chile flakes, Mozzarella and Provolone to sausage mixture. Stir well. Spread bread with pizza sauce. Fill with sausage-cheese mixture. Bake 20 minutes or until ingredients are heated through and cheese melts.