This frittata will impress you with looks and flavors, and fill you with pride at what you made. Rich, nutty fontina is combined with spinach and mushrooms, and baked with tart tomatoes on top. Finished with light dollops of pesto, this meal manages to be both rich and delicate, and the perfect end to your day.
Coarsely chop fontina. Cut mushrooms into ¼" slices. Coarsely chop spinach. Slice tomato into six ¼" rounds. Place tomato slices between two paper towels and gently press. This will help absorb excess moisture. Trim ends from baguette and cut into six slices on a slight angle. Combine liquid egg, ¾ the fontina (reserve remaining to top frittata), half the cream, ¼ tsp. salt, and a pinch of pepper in a mixing bowl
Cook the Vegetables
Heat 2 tsp. olive oil in a medium oven-safe non-stick pan (or cast iron skillet) over medium-high heat. Place mushrooms in hot pan and stir occasionally until lightly browned, 4-5 minutes. Add spinach to pan and cook until wilted, 30 seconds to 1 minute. Remove from burner. Reserve pan; no need to wipe clean. Allow vegetables to cool enough to handle.
Drain the Vegetables
Transfer vegetables to a clean towel and press to absorb any liquid. Reserve pan; no need to wipe clean.
Assemble the Frittata
Place vegetables and egg mixture in pan used to cook vegetables. Stir to evenly distribute ingredients. Lay tomato slices in mixture and sprinkle remaining fontina over assembled frittata.
Bake Frittata and Toast Bread
Place frittata in oven and bake until egg is set and cheese is bubbly, 15-18 minutes. Place bread slices on prepared baking sheet. Drizzle with ½ tsp. olive oil and season with a pinch of salt and pepper. Once frittata has baked 8 minutes, put bread in oven and toast until lightly browned, 5-7 minutes.
Finish the Dish
Carefully remove frittata from oven and place on a trivet. Wrap a towel around handle to indicate pan handle is hot. Garnish finished frittata with basil pesto. Serve frittata from pan alongside crostini.