Heat Oil: Heat 1 tablespoon of the olive oil in a large skillet over medium-high heat until the oil is hot and shimmering.
Season Scallops: Sprinkle the scallops evenly with the salt.
Sear Scallops: Arrange the scallops in the hot skillet in a single layer. Cook for 2 to 3 minutes per side, turning them once with tongs, until both sides are golden brown and the centers are just opaque.
Keep Scallops Warm: Transfer the cooked scallops to a large plate. Cover them loosely with aluminum foil and set them aside to keep warm.
Cook Onion: Add the remaining 1 tablespoon of olive oil to the same skillet. Add the chopped onion and cook over medium heat for 4 to 5 minutes, stirring often, until softened and lightly browned.
Add Seasonings: Stir in the crushed red pepper flakes and minced garlic. Cook for about 30 seconds, stirring constantly, until the garlic is fragrant.
Reduce Wine: Pour in the dry white wine. Use a wooden spoon to scrape up any browned bits from the bottom of the skillet. Simmer for 1 to 2 minutes, until the wine reduces slightly.
Add Broth: Pour in the chicken broth and stir to combine. Bring the mixture to a gentle simmer over medium heat.
Warm Beans: Stir in the drained cannellini beans. Simmer for 3 to 4 minutes, until the beans are heated through and the cooking liquid reduces slightly.
Wilt Spinach: Add the spinach and stir it into the bean mixture. Cook for about 2 minutes, until the spinach is wilted but still bright green.
Serve: Divide the warm Tuscan beans and spinach among serving bowls or plates. Arrange the seared scallops on top and serve immediately.