Follow these detailed steps to build your perfect grilled vegetable and lentil bowl. The process is broken down into cooking the lentils, preparing the vegetables and dressing, grilling to perfection, and assembling the final masterpiece.

Step 1: Cook the Lentils

1. Rinse: Place the lentils in a fine-mesh sieve and rinse them thoroughly under cold running water. This removes any dust or debris.
2. Combine and Boil: In a medium saucepan, combine the rinsed lentils with 4 cups of water or vegetable broth. Bring the mixture to a rolling boil over high heat.
3. Simmer: Once boiling, reduce the heat to low, cover the saucepan, and let the lentils simmer gently. Brown or green lentils typically take 20-25 minutes to become tender but not mushy. They should still have a slight bite.
4. Drain: Once cooked, drain any excess liquid from the lentils and set them aside. Avoid overcooking, as mushy lentils will detract from the bowl’s texture.

Step 2: Prepare the Dressing and Vegetables

1. Whisk the Dressing: While the lentils are simmering, prepare the dressing. In a medium bowl or a large jar, combine the tahini, olive oil, fresh lemon juice, minced garlic, maple syrup, Dijon mustard, salt, and pepper.
2. Emulsify: Whisk the ingredients vigorously until they are well combined. The mixture will likely be very thick at this stage.
3. Thin with Water: Add the cold water, one tablespoon at a time, whisking continuously until you reach a smooth, creamy, and pourable consistency, similar to a thin ranch dressing. Taste and adjust seasoning if necessary—more salt for flavor, more lemon for brightness, or more maple syrup for sweetness.
4. Prep the Vegetables: Wash and chop the bell peppers, zucchini, and red onion as described in the ingredients list. Keep the cherry tomatoes whole. If using a fresh ear of corn, you can either grill it whole or carefully slice the kernels off the cob after grilling.
5. Marinate the Vegetables: Place all the prepared vegetables in a large mixing bowl. Pour about half of the prepared tahini dressing over them. Gently toss with your hands or a large spoon until every piece is lightly and evenly coated. Reserve the other half of the dressing for serving. Let the vegetables marinate for at least 15 minutes at room temperature to absorb the flavors.

Step 3: Grill the Vegetables

1. Preheat Grill: Preheat your outdoor grill or indoor grill pan over medium-high heat (around 400-450°F or 200-230°C). A properly heated grill is essential for getting those coveted char marks without overcooking the vegetables.
2. Oil the Grates: Lightly oil the grill grates with a high-smoke-point oil (like avocado or canola oil) to prevent the vegetables from sticking.
3. Grill in Batches: Place the marinated vegetables directly on the hot grill in a single layer. You may need to do this in batches to avoid overcrowding the grill, which can cause the vegetables to steam instead of char.
4. Cook and Turn: Grill the vegetables for about 4-6 minutes per side. The goal is to get them tender-crisp with visible, dark grill marks. The zucchini and peppers will cook faster, while the onion wedges and corn on the cob might take a minute or two longer. The cherry tomatoes only need a few minutes until their skins start to blister and pop.
5. Remove and Chop: As the vegetables are cooked, remove them from the grill and place them on a large cutting board. Once they are cool enough to handle, chop the larger pieces (peppers, zucchini, onion) into bite-sized chunks. If you grilled the corn on the cob, stand it upright on the cutting board and carefully slice the kernels off.

Step 4: Assemble the Bowls

1. Create the Base: Divide the cooked lentils evenly among four large bowls.
2. Add the Vegetables: Arrange a generous portion of the mixed grilled vegetables over the bed of lentils in each bowl. Try to get a colorful mix of all the different veggies.
3. Drizzle and Serve: Drizzle the remaining creamy tahini dressing generously over the vegetables and lentils. Serve immediately while the vegetables are still warm.