A lunchtime bowl includes white beans and broccoli, two foods high in fiber, which can lower cholesterol and may help prevent type-2 diabetes. Tomatoes bring lycopene to the substantial salad.
Preheat oven to 375 degrees. Toss together broccoli, half the garlic, 2 teaspoons oil, and 1/4 teaspoon salt, and arrange on a rimmed baking sheet. Roast until broccoli is just tender, 15 to 20 minutes. Transfer to a plate; let cool completely.
Toss together tomatoes, remaining garlic, the oregano, red pepper flakes, remaining 1/4 teaspoon salt, and 1 teaspoon oil. Arrange on baking sheet. Roast until tomatoes have softened and skins begin to wrinkle, 15 to 20 minutes. Transfer to a plate; let cool completely.
Whisk mustard, vinegar, and lemon juice in a small bowl. Whisk in remaining 2 teaspoons oil; season with pepper.
Just before serving, toss together beans, broccoli, tomatoes, spinach, and dressing. Salad can be refrigerated in an airtight container up to 8 hours.
The ingredients can be prepared the day before and refrigerated.