How to Make It
Preheat the oven to 400°. In a large bowl, whisk both flours with the sunflower seeds, pumpkin seeds, baking powder and salt. Stir in the buttermilk and hot water just until the dough comes together. Scrape the dough onto a parchment paper–lined baking sheet and shape into an 8-inch round. Bake for about 40 minutes, until golden and cooked through and the bread sounds hollow when tapped. Transfer the bread to a rack to cool completely.
In a medium saucepan, cover the eggs with 2 inches of water and bring to a rolling boil. Cover, remove from the heat and let stand for 10 minutes. Transfer the eggs to ice water to cool, then drain, peel and lightly mash them.
In a large bowl, whisk the mayonnaise with the sour cream, mustard and honey. Stir in the shallot, scallion and lovage and season with salt and pepper. Add the eggs and mix well, mashing with the back of a fork. Spread on the bread and serve.
Barley flour is available at health food stores and from bobsredmill.com.