5 tablespoons extra-virgin olive oil, divided
3 garlic cloves, thinly sliced
1/4 teaspoon dried crushed red pepper
1 large bunch greens (such as spinach, mustard greens, kale, or broccoli rabe; about 1 pound), thick stems removed, spinach left whole, other greens cut into 1-inch strips (about 10 cups packed)
1 cup (or more) vegetable broth or low-salt chicken broth
1 15-ounce can cannellini (white kidney beans), rinsed, drained
1 teaspoon (or more) Sherry wine vinegar