Preheat oven to 375 degrees. Grease the insides of the cups of a 12-cup muffin tin with coconut oil, butter or lard.
Heat more coconut oil, butter or lard in a cast-iron skillet. When hot, add the chopped leeks and zucchini, and sauté till soft. Add the oregano and dried basil, as well as salt and pepper, and stir to combine.
Divide the cooked zucchini-leek mixture among the muffin cups. Top with a generous tablespoon of the grated cheese.
In a large bowl, add the cream. Break the eggs into another bowl, and whisk into the eggs the three powders. Add the eggs a little at a time to the cream, stirring each time till well-blended.
Fill each muffin cup with the egg-cream mixture, leaving about a quarter-teaspoon from the top. Bake about 30 minutes until Zucchini Cups are firm and golden.