Leek & Mushroom Tart (Gluten-Free)

Ingredients

• 1 cup almond meal (about 100 grams)
• 1 cup tapioca flour (about 100 grams)
• 1/2 cup butter (90 grams, salted)
• 1/2 teaspoon salt
• 1/4 teaspoon pepper
• 1 garlic clove (finely diced)
• 1 teaspoon thyme leaves (fresh or dried)
• 1 egg
• Olive oil for cooking
• 1 leek (sliced into thick circles (white and pale green parts))
• 250 g button mushrooms (0.5 lb., sliced)
• 1/4 teaspoon salt
• A pinch of pepper
• 1/2 teaspoon lemon zest
• 1 garlic clove (crushed or diced)
• 1 tablespoon lemon juice
• 5 large eggs (whisked)
• Optional: 50 g / 2 oz. Cheddar cheese (grated)