Slice the zucchini in half lengthwise and scoop out some of the center to provide extra room for the filling. Heat a griddle pan over a high heat and add the zucchini slices cut side down. Cook for 3-4 minutes each side until tender and char lines appear.
Step 2
Whilst the zucchini is cooking, heat the olive oil in a skillet over a medium heat. Add the beef and cook until just browned. Crush the garlic and add to the beef and continue to cook until the garlic is tender and the beef is well browned.
Step 3
Divide the beef between the two zucchini boats.
Step 4
Finely dice the onion and tomato and scatter over the beef.