Suggest High calorie veg breakfast ideas.

Once I add berries, Greek yogurt, nuts, hemp hearts, ground flax seed, blackstrap molasses, and walnuts to my oatmeal, and have coffee with lotsa milk alongside, it adds up to over 600 calories. If you don't eat dairy at all, then vegan yogurt-equivalent and plant milk would probably get you there, too.

Another option would be protein pancakes with nuts in/on them and some kind of calorie-dense topping, maybe sliced bananas and maple syrup.

I've been working on increasing my intake. Breakfast right now is

fruit (usually an apple), oatmeal with yogurt/cottage cheese, protein powder, hemp seeds and peanut butter. Since you said no peanut butter, you could do trail mix. Or have a glass of milk. Or a protein bar on the side.

If you don't like oatmeal - cereal and milk with a side of scrambled eggs with cheese and guacamole

Or, you could do a higher calorie protein bar (Clif Builder Bars is decent), glass of milk, fruit and hard boiled eggs.

Or, you could do savory - chicken, bacon and potatoes

Or baked potato, sour cream, cheese and chicken strips

Or leftover pizza is always an option. Easy to transport and great cold.

Essentially, there are plenty of options. What do you like to eat already? It doesn't have to be "breakfast food." I used to eat beef jerky for breakfast. My fiance regularly eats leftover pasta for breakfast.

If you want to gain then eat more hard boiled eggs for the protein and calories. Throw in a baked potato for the calories and carbs. Maybe a 1/4 pound of sliced deli turkey