Groupby vs pivot_table in Pandas DF

Question

I am using Big Mart Sales Data set. https://www.kaggle.com/brijbhushannanda1979/bigmart-sales-data

The 2 concerning Features here are Outlet_Size and Outlet_Type.

Outlet_Size tells us whether Outlet is Small, Medium or High sized.
Outlet_Type tells us whether it is grocery, SupermaketType1,2 or 3.

I want to know count of each outlet type against each outlet size.

For ex. When I use group by, I get following result.

df.groupby(['Outlet_Type', 'Outlet_Size'])['Outlet_Size'].count()

Output:

Outlet_Type        Outlet_Size
Grocery Store        Small           528
Supermarket Type1    High            932
                     Medium          930
                     Small          1860
Supermarket Type2    Medium          928
Supermarket Type3    Medium          935

Name: Outlet_Size, dtype: int64

I wish to do similar thing using pivot table. Can someone show how to write pivot table for the same?