Drain the beans over a bowl and reserve the liquid. Put the white beans in a large skillet with just enough of their liquid to moisten them. Add 2 tablespoons of the olive oil and bring the beans to a low simmer. Keep them warm while you prepare the shrimp.
Heat 1/4 cup oil in a large skillet over high heat. Add the shrimp, season with salt and cook for about 1 minute, tossing frequently. Remove the shrimp with tongs to a bowl. Add the garlic to the pan and saute until the garlic browns. Add the serrano chile or chili flakes and cook for 1 minute. Add the tomato and basil and stir briefly, then add the lemon juice. Season with salt and pepper. Cook for about 1 minute, and then stir in the shrimp. Toss well and cook briefly to reheat the shrimp. Remove the shrimp mixture to a plate and sprinkle with parsley.
Spoon the white beans on a platter or individual plates. Drizzle them with the best olive oil you have, and then top with the shrimp. Serve warm.