Slice zucchini lengthways. Place in a bowl and sprinkle generously with flaky sea salt to draw out water and season the zucchini. Leave for 15 - 30 min. Rinse and pat dry. Trim root end of the scallions. Transfer to a baking sheet along with the scallions, and two cloves of garlic, skin on. Make a glaze by mixing together the maple syrup and olive oil, plus a pinch of flaky sea salt. brush the zucchini and scallions with half the glaze. Grill in an oven on medium-high, turning as needed and brushing on more glaze. Remove the quicker-cooking scallions first when they are soft and browned. The zucchini will take approx 10 min. to cook and brown a little, depending on the strength of your grill.
Meanwhile, to make the gremolata, roughly chop the hazelnuts, finely chop parsley and zest half a lemon. Add a little oil to a frying pan over medium heat. Add breadcrumbs and hazelnuts and fry until toasted. Remove from heat, let cool slightly and mix with the parsley, lemon zest, and a pinch of salt.
Squeeze the roasted garlic out of the skins into a bowl and mash into a paste with a fork. Add the ricotta, approx. 2 tsp lemon juice, to taste, and a pinch of salt. Whisk together with the fork until combined. To serve, spread ricotta into the center of the plate in a thick layer. Arrange zucchini and scallions on top, top with gremolata and finish with a drizzle of olive oil, and some dill.