In large oven-proof skillet, heat olive oil over medium high heat. Sauté potato, onion, zucchini and mushrooms for 5 minutes, stirring often. Add tomatoes, spinach and diced jalapenos and cook an additional 2 minutes. Remove from heat and set aside.
In medium bowl, whisk together eggs, cheese, milk and seasonings. Pour egg mixture over vegetables in skillet. Use fork to help incorporate egg mixture into vegetable mixture.
Bake at 350 degrees for 20 minutes or until frittata is set in center.