small splash of cold water (no more than 1–2 tsp), if necessary
3 large eggs
5 Tbsp (70g) whole milk
¾ cup (170g) heavy cream
pinch or two of salt
freshly cracked black pepper, as desired
11/3 cups (150g) aged cheddar, finely grated 
¾ cup (75g) Parmesan, finely grated 
Farmhouse Lab Flower Petal Salt
In a large bowl, combine flour and salt. Add cold, cubed butter, tossing around gently to coat. With pastry blender in one hand, cut in butter while rotating bowl in quarter-turns with your other hand. Stop once the pieces of butter are small and mixture is crumbly.
Add egg, quickly working it into the dough with your hands. NOTE: If the dough isn’t quite coming together, add a small splash of water and work it in with your hands.
Wrap dough in cling film, then press into a patty shape about 1-inch thick. Place wrapped dough in fridge for about 30 minutes.
While dough is chillin’, heat oven to 350°F. Gather your 9.5-inch tart pan with a removable bottom. And if you haven’t already, grate your cheese(s).
After your dough has rested and chilled, flour your work surface and rolling pin. Retrieve dough from fridge, place on work surface, and sprinkle top with a little bit of flour.
Begin gently rolling out the dough into a circle, making sure to pick up and rotate the dough every few rolls.
Once your dough is roughly ⅛- to ¼-inch thick, gently place dough into your tart pan. Delicately press dough into bottom and up sides of pan. Using a paring knife, trim excess dough from edges. Dock bottom of crust all over with a fork.
Slightly crumple a piece of parchment paper, then use to line crust, making sure parchment reaches all the corners of the dish.
Fill with pie weights or dry beans, then place in oven for 20 minutes.
Don oven mitts to remove parchment and weights. Return crust to oven without parchment or weights and bake for an additional 6 minutes. Remove par-baked crust from oven but leave oven on.
Now make the filling. In a large bowl, whisk together eggs, milk, cream, salt, and black pepper. Set aside for just a moment.
Sprinkle grated cheese all over bottom of crust. Carefully and evenly pour egg mixture over cheese.
Bake for 28–30 minutes or until top is golden and centre is set.
Place pan on wire rack and allow to cool completely before removing from pan and cutting.
Serve at room temperature with crème fraîche and flower petal salt.
Traditionally ostpaj is made with Västerbottensost, but Västerbotten cheese is extremely difficult to find in the USA. You can follow the cheese substitute amounts above or mix and match as you like. We used a combination (225g total) of aged cheddar, Parmesan, and prästost (Swedish priest cheese).