Brussels Sprouts Frittata with Arugula, Purple Potatoes, Manchego

Ingredients

• 1 tablespoon butter
• 1 tablespoon avocado oil (or olive oil)
• 1/2 cup shaved brusselsl sprouts (or sliced thinly)
• 4 purple potatoes
• 2 tablespoons cheese (Manchego or White Cheddar)
• Handfull arugula
• 1/2 teaspoon salt (or to taste)
• 1/2 teaspoon black pepper (or to taste)
• 1 tablespoon shallot (or red onion) (finely diced)