Breakfast is important, and a healthy packed lunch is ideal. It isn't good to skip meals, and preferably it works better if all meals are as evenly spaced as possible. I personally find it hard to space out my meals because we don't tend to eat till gone 7pm in the evenings, and this has an effect on my fasting levels the following morning, but not much I can do about it.
There are several different forms of diet for Type 2's, but all of them have one thing in common - reduced carbs.
Packed lunches - eggs, tinned salmon, cold meats, cheese, cherry toms, chicken, mayonnaise or an olive oil dressing, salad stuff. Anything along those lines. Maybe a yogurt (plain) with a few strawberries added to it. No bread if it can be avoided, and if it can't, then a low-carb bread with butter on and only 1 slice.
As for your evening meal, you need to seriously cut down on or avoid the spag bol and oven chips. These are too heavy in carbohydrates.
For diabetics, carbs = sugar. All carbs turn to sugar once inside the system. Some are worse than others. For example, rice, pasta, potatoes, bread, pastry and batter need to be greatly reduced portion-wise. What I suggest is that he eats a meal, having tested his levels immediately before eating. Then test again 2 hours after the first bite (with nothing eaten or drunk in between). Look at the difference between the before and after, and work at getting this rise down. If you keep a strict food diary of everything eaten and drunk, with portion sizes, then records the blood levels alongside, you will soon get a picture of what is suitable for him. You can then try the same meal again with reduced portions of the carbs, and keep doing this until you reach a carb amount he can cope with. He may find he has to completely avoid some carbs but might manage others in smaller quantities.
Only by testing will he (and you) learn what he can and can't eat to control his levels. We are all different, and we all react in different ways to different carbs.