- *Prawn Biryani*: Weigh out precisely 150 grams - 210.59 calories

Total 'Lunch' calories = 210.59

Grand Total Calories = 210.59 

Since prawn biryani itself won't be enough to reach the set target '325' calories, you may add additional items to your meal such as:

- *Raw Mixed Vegetables*: Have about 200 grams - 90 calories. 

- *A Small Orange*: 1 fruit - 62 calories. 

Then the total 'Lunch' calories will be: 210.59 (Prawn Biryani) + 90 (Mixed Vegetables) + 62 (Orange) =  362.59 calories.

As this calculation is slightly over the target, it's suggested to decrease the portion of mixed vegetables to about 150 grams (67.5 calories), keeping the rest ingredients unaltered. Then the total calories will be: 210.59 (Prawn Biryani) + 67.5 (Mixed Vegetables) + 62 (Orange) =  340.09 calories.

For the sake of precision and accuracy, the remaining 15.09 calorie difference can be subtracted from the prawn biryani which will be around 137 grams instead of 150 grams.

Now, here's the accurately calculated meal plan:

- *Prawn Biryani*: about 137 grams - 195.59 calories
- *Raw Mixed Vegetables*: about 150 grams - 67.5 calories
- *A Small Orange*: 1 fruit - 62 calories

Total 'Lunch' Calories = 195.59 (Prawn Biryani) + 67.5 (Mixed Vegetables) + 62 (Orange) = 325.09 calories

Nutritional Breakdown:
- Fat: Aim for 15% to 20% of grand total calories, which equals to 48.76 to 65.01 calories
- Carbohydrates: Target 50% to 60% of grand total calories, which equals to 162.54 to 195.05 calories
- Protein: Ensure 20% to 25% of grand total calories, which equals to 65.01 to 81.27 calories