In large bowl, mix flour and salt.

Cut in cold butter using pastry cutter or fork until mixture resembles coarse crumbs.

Stir in sour cream and just enough ice water to bring dough together.

Knead briefly, form into disc, wrap and chill for 30 minutes.

In skillet, heat olive oil over medium heat.

Add onions and garlic, sautéing until fragrant and translucent.

Add your vegetables of choice, season with salt, pepper and thyme. Cook until tender.

Remove from heat and let cool slightly.

Preheat oven to 400 degrees F.

On floured surface, roll dough into12-in circle.

Transfer to parchment-lined baking sheet.

Spoon filling into center, leaving 2-in border. Sprinkle with cheese.

Fold edges over filling, pleating as needed.

Brush crust with beaten egg and sprinkle with flaky salt or seeds.

Bake for 40–45 minutes, or until golden brown.

Let cool for 10 minutes before slicing.