Counting On These Cheese Omelette To Help Me

I am a girl and I am pretty skinny. My BMI is fine, but it's at the border. I definitely need to gain some weight. These days I make myself a nice cheese omelet every evening to add some calories. The best part is that it tastes like a pizza when I add a lot of cheese! I enjoy my cheese omelet with my evening tea. For breakfast, I eat a normal omelet with whole wheat bread.

Here is what goes in my cheese omelet:
-1 egg
-1 green chili
-1 tomato
-Mozerella cheese
-Cheddar Cheese
-A little salt
-A little milk

I was thinking about increasing the number of eggs, so I can gain weight faster. Should I?