Mini Meal

I have a daily 4 – 5 hour eating window.
There are many days where I can easily postpone lunch for an additional two hours.
On these days I don’t need a meal so close to dinner but I need to eat a little something.
I’m trying to figure the best choice for this “mini meal”.
Should I keep my mini meal to veg, protein and fat as if it was a meal, only much smaller, or maybe just eat some fat to get me to dinner?