The unconventional toppings make these burgers special: Pickled beets add earthiness and tang; grilled pineapple rings add sweetness; and fried eggs add richness. Slideshow: More Burger Recipes
Preheat the oven to 350°. In a small bowl, coat the beet with 1 teaspoon of the olive oil and sprinkle with a generous pinch of salt. Wrap the beet in foil and roast in a pie plate until tender, 1 hour. Let cool, then peel the beet and slice it 1/4 inch thick. Transfer to a heatproof bowl and add the onion.
In a medium saucepan, combine the white vinegar, rice vinegar, sugar and 2 1/2 tablespoons of salt. Bring to a boil over moderate heat, stirring to dissolve the sugar. Pour the brine over the beet and onion and let cool, about 1 hour.
Light a grill or preheat a grill pan. Coat the pineapple slices with the remaining 1 teaspoon of olive oil and a pinch each of salt and crushed red pepper. Grill the pineapple until warm and lightly charred, 2 minutes per side. Transfer to a plate and keep warm.
In a large nonstick skillet, melt the butter. Add the eggs and cook over moderate heat until the whites are set and the yolks are slightly runny, about 3 minutes. Remove from the heat and season with salt.
Layer the pickled beets and onions on April’s Essential Burgers. Top with the grilled pineapple rings and the fried eggs and serve.
The pickled beets can be refrigerated for up to 2 weeks.
Make April's Essential Burgers