1 package (12 oz.) wide egg noodles
1 lb. baby red potatoes (8 to 10), cut into 1/4-inch slices
8 oz. haricots verts (thin green beans), cut on an angle into thirds
2 tbsp. olive oil
3 tbsp. butter
1 large shallot, finely chopped
4 cloves garlic, chopped
¼ cup flour
½ cup white wine
2 cups whole milk or half-and-half
2 cans (5 to 6 oz. each) sustainable tuna, drained and flaked
½ cup chopped pitted Niçoise olives
¾ cup grated Parmigiano-Reggiano
¾ cup grated Gruyère
1 tsp. herbes de Provence
4 hard-boiled eggs (store-bought or homemade), sliced or chopped
¼ cup chopped drained cornichons
Preheat the broiler. Or position a rack in the center of the oven and preheat to 450°.
Bring a large pot of water to a boil for the noodles. Salt the water and add the noodles. Cook for 2 minutes. Add the potatoes and cook for 3 minutes. Add the haricots verts. Cook until the potatoes and noodles are tender and the green beans are crisp tender, about 2 minutes more. Drain and return the noodles and veggies to the hot pot.
Meanwhile, in a large skillet, heat the oil, two turns of the pan, over medium to medium high. Add the butter. When it melts, add the shallot and garlic and stir until softened, a minute or two. Whisk in the flour, then the wine. Whisk in the milk; season with salt and pepper. Cook, stirring occasionally, until the sauce is thick enough to coat the back of a spoon, about 2 minutes. Stir in the tuna and olives and cook, stirring occasionally, until warmed through, about 2 minutes. Gently mix the sauce into the noodles and vegetables. Transfer to a 3-quart casserole dish. Top with the cheeses. Sprinkle with the herbes de Provence. Bake the casserole until bubbly and browned in spots, about 3 minutes. Top with the eggs and cornichons.