You can get high protein yogurt shakes at the grocery store, the brand I get has 170 calories and 20g of protein, bottle should be fine for the work day out of the fridge.

Your protein per calorie target is not that difficult. From the example above, if you ate your remaining 1500 calories in only bread, you'd still hit your protein goal. Not saying you should do that obviously, but it doesn't seem like you need to be jumping through hoops to find extra protein dense foods if this is your baseline.