Tkinter OptionMenu: How to configure font size of drop down list?

I have an option menu list with a lot of entries to be used on a touch screen device. I am able to change the font size of the selected category with PopMenue.config(font=[something]), but when selecting the drop down menu the entries appear in the default small font:

Example Pic - red frame surrounds text to increase font

How can I amend the font size from the drop down menu entries (red frame)?

Code snippet:

helv36 = tkFont.Font(family='Helvetica', size=30, weight=tkFont.BOLD)
popupMenu.config(font=helv36)

You have to use the nametowidget() method to get the widget object corresponding to the dropdown menu widget, then set its configuration.

Here's a runnable example:

import tkinter as tk
import tkinter.font as tkFont

root = tk.Tk()
root.geometry('300x200')

helv36 = tkFont.Font(family='Helvetica', size=36)
options = 'eggs spam toast'.split()
selected = tk.StringVar(root, value=options[0])

choose_test = tk.OptionMenu(root, selected, *options)
choose_test.config(font=helv36) # set the button font

helv20 = tkFont.Font(family='Helvetica', size=20)
menu = root.nametowidget(choose_test.menuname)  # Get menu widget.
menu.config(font=helv20)  # Set the dropdown menu's font
choose_test.grid(row=0, column=0, sticky='nsew')

root.mainloop()

Here's are two screenshots showing the default vs modified dropdown menu text sizes: