Clone the shape two times (Ctrl k, Ctrl k). Move the second clone upwards about 10 pixels. Select both clones and Arrange > Combine Shapes > Subtract Shapes (Ctrl 2).
Change the fill color to the dark red (RGB 90, 0, 0).
Select the new shape and apply 6 pixels of feathering using the Feathering slider on the Infobar. Apply 3 pixels of feathering to the dollop.
Select the Freehand and Brush Tool (n) again, and draw some highlight shapes. Apply the two colors shown. Group the top highlight shapes then group the bottom highlight shapes.
Switch to the Transparency Tool (F6). Click on the top highlight shape and drag downward as shown. Apply two pixels of feathering. Repeat this with the bottom highlight shape. These highlights make the dollop of ketchup look liquid and glossy. Group all the fry objects.
Select the Shape Tool, and create a shadow shape shown above. Apply a Linear, Mix transparency and then add 3 pixels of feathering.