Preheat the oven to 425°. In a medium saucepan, heat 1 tablespoon of the olive oil. Add the garlic, onion, carrot and celery and cook over moderately high heat, stirring occasionally, until the vegetables are starting to brown, about 5 minutes. Add the water, lentils and bay leaf and bring to a boil. Simmer over low heat, stirring a few times, until the lentils are tender, about 25 minutes. Set a colander over a large bowl and drain the lentils; transfer the cooking liquid to a cup. Discard the bay leaf.
Meanwhile, in a small saucepan, cover the sun-dried tomatoes with water and bring to a boil. Simmer over low heat until softened, about 5 minutes. Drain and cool, then cut into 1/4-inch dice.
In the large bowl, mix the mint with the vinegar, honey and 2 tablespoons of the olive oil. Stir in the lentils and tomatoes. Season with salt and pepper and stir in 2 tablespoons of the reserved lentil cooking liquid; add more of the liquid if the lentils seem dry.
In a 9-inch square baking dish, toss the shrimp with the remaining 1 tablespoon of olive oil and season with salt and pepper. Spread the shrimp in the baking dish and roast for about 6 minutes, or until just cooked. Mound the lentil salad on plates, top with the shrimp and drizzle the roasting juices over them.