Preheat oven to 375 degrees.
Lightly oil a large rimmed baking sheet.
In a small bowl, whisk together olive oil, Dijon mustard, sherry or cider vinegar and agave or honey until ingredients emulsify, about a minute. Add chopped dill and give another quick whisk. Set aside.
Spread sliced zucchini, onion and pepper on the baking sheet, taking care not to crowd the vegetables. Brush generously with the dressing, using about half. Reserve the remainder for serving.
Roast vegetables for about 30 minutes. Give them a stir and a flip about halfway through. They should be slightly tender at this point. Give them another 10 to 15 minutes, then remove from the oven and set aside for a few minutes to cool.
Spread greens on a platter. Lay the roasted vegetables on top. Sprinkle sliced radishes and chopped almonds over all, plus the additional chopped dill for garnish, if you like, and drizzle the the remaining dressing on top.