Preheat oven to 425°F. Trim beets and place in a large piece of foil. Tightly crimp foil to seal and roast until tender, about 1 hour. Cool, peel and cut into 1-inch dice.
Melt butter in a small skillet over medium-high heat. Add almonds, lower heat to medium and cook, stirring often, until light golden brown, about 3 minutes. Drain on paper towels and season with salt and pepper.
Combine vinegar, lemon juice and mustard in a large bowl. Whisk until blended and smooth. Whisk in both oils and season with salt and pepper. Pile lettuce on top of dressing and toss well to coat. Toss in beets, sprinkle with goat cheese and almonds, and serve cold.