1. Prepare Your Ingredients (Mise en Place – approx. 2 minutes):
* Spinach: If using baby spinach, give it a quick rinse and pat dry. If using larger spinach leaves, roughly chop them. If you opted for garlic or shallots, mince/chop them now.
* Feta: Crumble your feta cheese if it isn’t already.
* Eggs: Crack the eggs into a small mixing bowl. Add the optional milk/cream (if using), a tiny pinch of salt (remember the feta!), and a generous grinding of black pepper.
* Whisk: Whisk the eggs vigorously with a fork or a whisk for about 30 seconds to a minute, until the yolks and whites are fully combined and slightly frothy. You want to incorporate some air for a lighter omelette. Don’t over-whisk to the point of being completely pale; some streaks of yolk are fine.

2. Sauté the Aromatics and Spinach (approx. 2-3 minutes):
* Place a non-stick skillet (an 8-inch or 10-inch pan is ideal for a single omelette) over medium heat.
* Add the butter or olive oil to the pan. Once the butter is melted and foamy or the oil shimmers, add the optional minced garlic and/or chopped shallots. Sauté for about 30 seconds to a minute until fragrant, being careful not to burn the garlic.
* Add the fresh spinach to the pan. It will look like a lot, but it wilts down quickly. Stir or toss it gently for 1-2 minutes, just until it’s wilted and bright green. If any excess liquid releases from the spinach, allow it to evaporate quickly.
* Season the spinach lightly with a tiny pinch of salt and pepper if desired, though often the feta provides enough salinity.
* Remove the wilted spinach (and aromatics) from the pan and set aside on a small plate. This prevents the spinach from overcooking and releasing too much water into the eggs. Wipe the pan clean with a paper towel if there are any burnt bits, adding a tiny bit more oil/butter if needed.

3. Cook the Omelette (approx. 3-4 minutes):
* Return the skillet to medium heat (or medium-low if your stove runs hot). It’s crucial the pan isn’t too hot, or the eggs will cook too quickly and become tough.
* Give the whisked eggs one last quick stir and pour them into the heated pan.
* Let the eggs cook undisturbed for about 30-60 seconds, or until the edges begin to set. You’ll see bubbles forming.
* Using a heat-resistant spatula, gently push the cooked egg from the edges towards the center, tilting the pan so that the uncooked egg flows underneath. Repeat this around the edges of the pan until most of the liquid egg has flowed to the bottom and the top is still slightly wet but mostly set. This process should take about 1-2 minutes.

4. Add Fillings and Fold (approx. 1 minute):
* Once the omelette is mostly set but still slightly moist on top, sprinkle the cooked spinach mixture evenly over one half of the omelette.
* Scatter the crumbled feta cheese over the spinach. If using fresh herbs like dill, sprinkle some on now.
* Carefully, using your spatula, fold the unfilled half of the omelette over the fillings. Press down gently with the spatula to seal the edges.

5. Finish Cooking and Serve (approx. 30 seconds – 1 minute):
* Let the omelette cook for another 30 seconds to a minute, just until the feta is slightly warmed and beginning to melt, and the omelette is cooked through to your liking. Some prefer it a little soft in the center, others fully set.
* Gently slide the omelette from the pan onto a warm plate.
* Garnish with a little extra crumbled feta, a sprinkle of fresh herbs, or an extra crack of black pepper if desired. Serve immediately and enjoy your masterpiece!