Preheat oven to 350°F and set a rack in the middle position.
In a large bowl whisk together eggs and sour cream. Add milk, mustard powder, oregano, salt and pepper and whisk to fully combine. Stir in half of the cheese. Set aside.
Add oil to a 10" cast-iron skillet over medium heat. When hot add the onion and garlic and sauté until starting to soften about 3 minutes.
Add broccoli and water to the pan and cover to steam the broccoli until just tender about 3 minutes. Remove lid and stir in green onions and whisked egg mixture. Allow to cook over medium-low on the stove for 3-5 until the edge is just starting to set. Sprinkle with remaining cheese and place in the oven. Bake for 12-15 minutes until just starting to set in the centre (it should jiggle a little in the centre). Remove from oven and allow to rest for 5-10 minutes.
Cut into desired wedges and serve immediately.
-Use frozen broccoli if that's what you have, just be sure to thaw completely and pat dry before using. Add to skillet after cooking the onion and cook just to warm (don't add water) before continuing with the recipe.
-Gruyére cheese would also be a nice substitute for the cheddar.
-The cooked frittata will keep for several days well wrapped in the fridge and can be rewarmed gently in the microwave. It does not freeze well.
Preheat oven to 300℉. Remove stem and quarter tomatoes. In a medium bowl toss together tomatoes, garlic, smoked paprika, olive oil and a generous sprinkle of salt and pepper. Arrange tomatoes skin side down and garlic in a single layer on a parchment lined sheet pan with edges. Roast for 1 1/2 hours. Remove from oven an allow to cool on pan.
Using a food processor pulse flour, oregano, salt, pepper and butter until butter is broken down and mixture is crumbly. Add cheeses and pulse 2-3 times to combine. In a small bowl whisk together egg, vinegar and 1 tbsp cold water. With the processor running add gradually until mixture pulls away from the edge. Add remaining 1 tbsp of cold water if necessary. Remove dough from processor and form into an approximate 1" thick disk. Wrap with plastic wrap and chill for at least an hour but can be made and chilled one day ahead. Allow to be at room temperature for 20 minutes prior to rolling.
Preheat oven to 400℉. Roughly chop garlic and tomatoes into bite site chunks. Roll pastry into a free form circle approximately 14" in diameter and 1/8" thick. Move pastry to a parchment lined baking sheet. Leaving a 2" border arrange roasted tomatoes and garlic in the center of the pastry. Wrap edges over top of tomatoes, creasing slightly as you go. Top center with provolone and basil. Whisk egg with 1 tbsp of water and brush on pastry. Bake for 30 minutes until golden. Allow to rest 2-3 minutes. Cut into slices and serve immediately.