Preheat the oven: Preheat to 200°C (400°F). Grease a 23x23x8 cm baking dish with olive oil.

Whisk the eggs: In a large mixing bowl, whisk together eggs, cream or milk, salt, pepper, and herbs until well combined.

Sauté the leeks: In a frying pan or skillet, heat olive oil over low-medium heat. Add the sliced leek and cook, stirring occasionally, for about 10 minutes until soft.

Add the garlic: Add minced garlic and sauté for another 1 minute until fragrant. Remove from heat.

Add asparagus: Stir in chopped asparagus to the warm pan to lightly soften with the residual heat.

Add cheese to eggs: Add crumbled goat cheese to the egg mixture and stir gently to combine.

Assemble the frittata: Spread the sautéed vegetables evenly in the greased baking dish. Pour the egg mixture over the top.

Bake: Bake for 30 minutes. Check center it should be just set with a slight wobble. If needed, bake 5 more minutes.

Rest: Let the frittata sit for at least 10 minutes before slicing and serving.