1k calories? That may not be enough to sustain. You should be at least 1,200 depending on your body, sex, age, etc. You should also be a lot higher on the protein. Are you using OMAD to lose weight or to gain some of the other health benefits?
Protein powder is very affordable and gives you about 30g a scoop. I normally get soy as I don’t handle dairy too well.
For actual food, chicken breast is a good option or any other lean meat or fish.
High protein meal, be it chicken breast or steak, I like to have topped with 3 fried eggs. A salad consisting of arugula and tricolour coleslaw cabbage, cubed avocado and walnuts tossed in a nutritional yeast vinaigrette. Beverage with this meal is a protein shake with a scoop and a half of protein, and I like to add a scoop of glutamine to it.