Do you cook your vegetables before adding it into an omelette?

You cook them to the desired level of doneness before adding them to the omelette as an omelette only takes a couple of minutes until it's cooked. Not enough time for anything to cook inside it apart from say spinach wilting. read more

Definitely, all hard vegetables need to be cooked before adding. This way they are cooked through properly, and taste better, because you are adding carmelization to cooked vegetables. Also this reduces the water in the vegetables so that they don't make your omelet soggy. read more

Add 3/4 cup water and stir until the mixture is runny. Mix in chopped bell peppers and chopped onion. Set aside. Heat a pan over medium flame. Add 1 teaspoon oil and coat well. Once hot, add the batter. Make sure the batter is spread evenly across the pan (do not mix/stir). Close the lid and cook for 4–5 minutes on low-medium heat settings. read more

If you mean onion and green pepper, the most commonly used vegetables in meatloaf, they do not have to be cooked before adding. They will cook as the meatloaf cooks. As to any other vegetables, it would depend on what they are. I personally have had no experience with adding any vegetables except onion and green pepper to meatloaf. read more