How to make a Button using the tkinter Canvas widget?

Question

I want to obtain a button out of a Canvas. I've tried to pack the canvas in the button widget, but that didn't work. Googling a bit, I've found (here: How do you create a Button on a tkinter Canvas?) that the Canvas method create_window might help. But there should be something wrong in the way I'm using it.

import Tkinter

DIM = 100

root = Tkinter.Tk()
frame = Tkinter.Frame(root)

button = Tkinter.Button(None, width=DIM, height=DIM, command=root.quit)

circle = Tkinter.Canvas(frame, width=DIM, height=DIM)
circle.create_oval(5, 5, DIM-5, DIM-5, fill="red")
circle.create_window(0, 0, window=button)

frame.grid()
circle.grid(row=1, column=1)

root.mainloop()

If I erase the create_window line, I can se my painting but I can't (obviously) click on it. But in this way, the button widget cover my circle and shows a sad empty button.

Basically, I want to create a button with a red circle painted inside.