1/2 cup plus 1 tsp. canola oil
Salt and freshly ground black pepper
4 1-lb. lobsters
2 tbsp. champagne
2 tbsp. champagne vinegar
3⁄4 tsp. dijon mustard
1⁄2 tsp. finely chopped shallots
6 cups mesclun greens
3-4 ripe avocados, such as hass, pinkerton, or macarthur
1. Heat oven to 350°. Toss beets with 1 tsp. of the oil; season with salt and pepper to taste. Wrap in a foil package. Roast until tender, about 45 minutes. Chill beets.
2. Bring a large pot of generously salted water to a boil over high heat. Add lobsters and cook until bright red and cooked through, about 5 minutes. Drain and cool lobsters, then twist off each tail, gently crack the shell, and remove the meat in one large piece; chill. Repeat process with claws. (Reserve knuckle meat and remaining lobster for another use.)
3. Whisk together champagne, champagne vinegar, dijon mustard, shallots, and salt and pepper to taste in a bowl. While whisking constantly, drizzle in remaining 1⁄2 cup of oil to form a smooth dressing. Toss greens with some of the dressing; arrange in center of 4 plates. Arrange chilled beets, some grapefruit segments, and 12 avocado slices around each portion of greens. Divide lobster tails and claws between plates. Drizzle each salad with remaining dressing.