Preheat your oven to 375 F. Scrub the carrots clean, trim the stems (leaving about an inch for a decorative look), then place them on a baking sheet. Toss the carrots with the thyme sprigs, salt, pepper and olive oil and place in the oven. Roast for 30 minutes, shaking the pan a few times during baking, until the carrots are soft and tender, and just beginning to brown. Mix the honey, orange juice and vinegar together, then pour over the carrots and roast for another 5 minutes, or until it forms a thick glaze on the carrots. Remove from the oven.
While the carrots are roasting, toast the hazelnuts. You can do this in the skillet that you will toast the breadcrumbs in in step 3, or in the hot oven with the carrots. If oven-roasting, place them on a baking sheet and pop them in the oven for 8-10 minutes, then remove and when cool enough to handle, rub off as much of their skins as possible. If toasting in the skillet, place them over medium heat in the dry skillet and cook for 10 minutes, shaking the pan frequently, until the skins begin to loosen and the hazelnuts become toasty. Either method, remove from the heat and let cool.
Chop the hazelnuts finely, then add to a small bowl with the parmigiano, coriander, lemon zest, lemon juice, garlic clove and salt.
Pour the 2 tablespoons of olive oil in a skillet and heat over medium high heat. Add the breadcrumbs and cook, stirring, until they are browned and toasted. Let them cool down, then pour into the bowl and combine with the hazelnut mixture.
To serve, place the carrots on a platter and top with half of the breadcrumb mixture. Serve warm, or at room temperature, passing extra topping at the table.