Answer:
Ishaan could make 7 possible combinations of meals.
Explanation:
Number of subsets in a set of n elements:
The number of subsets in a set of n elements is given by:

In this question:
3 dishes.

only one, two of them, or all three of the dishes.
Considering the dishes, there are no empty set(there cannot be an order with no dishes), so 8 - 1 = 7
Ishaan could make 7 possible combinations of meals.