Omelette Recipe (Easy, Fluffy, 10 Filling Ideas!)

Name: Omelette Recipe (Easy, Fluffy, 10 Filling Ideas!)
Prep time: 5 min
Cook time: 10 min
Total time: 15 min
Cuisine: French
Ingredients: 4 large Eggs; 1/4 cup Milk of your choice ((2% or whole milk, half and half, heavy cream, almond milk, or coconut milk)); 1/4 tsp Sea salt; 1 pinch Black pepper; 1 tbsp Avocado oil; 3 tbsp Onions ((diced finely)); 3 tbsp Bell peppers ((diced finely)); 3 tbsp Mushrooms ((diced finely)); 3 tbsp Tomatoes ((diced finely)); 1/2 cup Cheddar cheese ((shredded; omit for dairy-free)); 1/2 medium Avocado ((sliced thinly; optional, for topping)); Fresh herbs ((optional, for topping))