Combine all the ingredients for the dressing in a small jar or measuring cup. Whisk together, then set aside until ready to serve.

To cook the lentils, bring the liquid to a boil over high heat. Add the dry lentils, then reduce heat to a simmer and cook for 30 minutes, or until all liquid is absorbed. Once cooked, remove from heat and set aside to cool.

Prepare the vegetables. For the onion, slice crosswise to create thin slices, removing the outer skin. For the eggplant, slice crosswise to create thin, flat pieces. For the zucchini, slice in half lengthwise, then again into quarters to create long strips.

Bring your grill to medium-high heat. Brush the vegetables with olive oil, then lightly season with salt and pepper to taste. Grill for 2-3 minutes on each side, rotating as needed to avoid charring. Repeat as needed to grill all prepared pieces and achieve your desired level of doneness. Remove from the grill and set aside.

Repeat these steps with the ciabatta or baguette slices. Brush lightly with olive oil, then grill 1-2 minutes on each side to create grill marks. Remove from the grill and set aside.

As the cooked lentils and grilled veggies are cooling, prepare the salad by arranging the arugula or salad greens on a large platter. Cut the zucchini strips in half, then arrange over the salad greens along with the grilled onion and eggplant. Sprinkle with feta cheese and fresh sprigs of thyme (if using).

To serve, plate with two slices of the grilled bread, drizzle with the Honey Mustard Vinaigrette, and garnish with fresh lemon slices.