I used some html, css and responsive design

Try and make a separate css file and link to it from the html file. Also put content between the <li> tags. Like this

<ul>
            <li>2-3 large eggs</li>
            <li>Salt, to taste</li>
            <li>Pepper, to taste</li>
            <li>1 tablespoon of butter or oil</li>
            <li>Optional fillings: cheese, diced vegetables, cooked meats, herbs
            </li>
          </ul>

 <ol>
            <li><strong>Beat the eggs</strong>: In a bowl, beat the eggs with a pinch of salt and pepper until they are well mixed. You can add a tablespoon of water or milk for a fluffier texture.</li>
            <li><strong>Heat the pan</strong>: Place a non-stick frying pan over medium heat and add butter or oil.</li>
            <li><strong>Cook the omelette</strong>: Once the butter is melted and bubbling, pour in the eggs. Tilt the pan to ensure the eggs evenly coat the surface.</li>
            <li><strong>Add fillings (optional)</strong>: When the eggs begin to set at the edges but are still slightly runny in the middle, sprinkle your chosen fillings over one half of the omelette.</li>
            <li><strong>Fold and serve</strong> : As the omelette continues to cook, carefully lift one edge and fold it over the fillings. Let it cook for another minute, then slide it onto a plate.</li>
            <li><strong>Enjoy</strong>: Serve hot, with additional salt and pepper if needed.</li>
          </ol>