Peppery arugula and tart grapefruit are bright counterpoints to sweet seared sea scallops and salad greens, all in a tangy mustard vinaigrette. Have this feast-for-the-taste buds on the table in under 30 minutes!
Finely dice onion. Tear lettuce into bite-sized pieces. Remove thick stems from arugula.
With a sharp knife, remove skin and white pith from grapefruit. Separate grapefruit into segments.
Drizzle scallops with lemon juice and sprinkle with salt and pepper. Heat butter in a nonstick pan and cook scallops about 2 minutes on each side; add vermouth and cook another 1 to 2 minutes. Remove from heat.
To make vinaigrette, whisk oil, vinegar, mustard, and honey, until thickened slightly; add salt and pepper to taste.
Arrange lettuce leaves on individual plates and drizzle with vinaigrette. Top with diced onion and grapefruit segments. Arrange scallops on top.