How to Make It
Preheat the oven to 300°. Put the tomatoes in a small baking dish, cut side up. Add the basil, bay leaf, garlic and halved shallot. Add the olive oil and season with salt and pepper. Cover with foil and bake the tomatoes for about 2 hours, until very tender. Let cool slightly. Using a slotted spoon, transfer the tomatoes to a plate and break them up slightly. Reserve the tomato oil. Discard the basil, bay leaf, garlic and shallot.
In a small saucepan, heat 1 teaspoon of the tomato oil with half of the minced shallot and cook over moderate heat until softened, 2 minutes. Add the lentils and 3 cups of water; season with salt and pepper. Simmer over high heat until the lentils are tender, 15 minutes; drain and transfer to a large bowl. Stir in the vinegar, oregano, 1/4 cup of the tomato oil and the remaining minced shallot. Season with salt and pepper.
Heat a cast-iron grill pan. In a medium bowl, toss the green beans with 1 tablespoon of the tomato oil and season with salt and pepper. Grill over high heat, turning once, until lightly charred, 2 minutes.
In a large skillet, heat 1 tablespoon of the tomato oil. Add the diced pancetta and cook over moderately high heat, stirring occasionally, until lightly browned, about 6 minutes. Add the pattypans and the crushed red pepper, season with salt and cook for 1 minute. Add the roasted tomatoes and green beans and cook, stirring, for 1 minute. Spoon the vegetable mixture onto 4 plates and drizzle half of the lentil vinaigrette on top.
Add the arugula to the remaining lentil vinaigrette and toss. Mound the arugula on the green bean salad and serve.