1 pound baby red-skinned potatoes
1 clove garlic, smashed
Kosher salt
2 1/2 tablespoons extra-virgin olive oil
2 teaspoons chopped fresh rosemary
2 teaspoons chopped fresh thyme
1 teaspoon finely grated lemon zest
1 1/2 pounds beef tri-tip, cut lengthwise into 4 steaks
1 tablespoon fresh lemon juice
1 tablespoon finely chopped fresh parsley
Freshly ground pepper
2 medium zucchini, sliced diagonally 1 inch thick