This frittata is made with spinach and mushrooms and topped with bacon. Be sure to add the bacon to the frittata right before transfering it to the oven - the bacon will retain a bit of texture and color.
Heat a 10.5” to 12” (26 cm to 30 cm) skillet over medium-high heat. Add bacon and saute until crisp, 6 to 7 minutes. Transfer bacon to a paper-towel lined plate.
Drain off all but 1 Tbsp / 15 mL of bacon grease from the pan. Return pan to heat. Add mushrooms and saute until mushrooms are tender and brown, 4 to 5 minutes.
Add spinach and saute until spinach is wilted, ~3 minutes more.
Pour in eggs and stir until ingredients are all mixed through. Sprinkle bacon over top of frittata.
Transfer frittata to the oven. Bake for 20 to 25 minutes until eggs are set and inserted knife comes out cleanly.
While frittata cooks, whisk together mustard, honey, and vinegar. Add oil while whisking. Toss with arugula just before serving.
Slice frittata and serve with salad on the side. Enjoy!