Place the steak in a large bowl or zip top bag. Mix all the marinade ingredients in a mixing cup and pour it over the steak. Allow to marinate for 1 hour or overnight.
Place all the chimichurri ingredients in a food processor and pulse until a sauce is formed. Store in the fridge until ready to use.
Preheat oven to 350 degrees.
Cut the zucchini in half the long way, then use a paring knife to make cross-hatch slices on the flat cut side of the zucchini. Season the cut side with salt and pepper making sure some seasoning gets into the slices you made. Place cut side down on a paper towel for 15 minutes.
Preheat a large skillet to high heat with a little olive oil and place the zucchini cut side down into the pan. Cook for about 3-5 minutes to deeply brown the zucchini. Remove from the pan and place cut side up on a baking sheet. Repeat with any remaining zucchini that didn't fit in the pan on the first batch.
Once all the zucchini slices are on the baking sheet, bake them for about 10 minutes until desired tenderness.
Preheat a grill or grill pan to medium high heat. Cook the steak for about 5-7 minutes on each side to reach a medium doneness.
Remove from heat and slice the steak against the grain. Serve with the zucchini and chimichurri.