1. Mix the water, 1 teaspoon of honey, and the yeast into the bowl of a stand mixer. If making the bread by hand, mix them together in a large bowl. Let stand 5 to 10 minutes. Little bubbles should start to appear. (If not, you need to replace your yeast and start again.)
2. In a separate bowl, mix together the whole wheat and rye flours with the salt. Attach the dough hook to the mixer, or use a wooden spoon if mixing by hand. Stir the 1/4 cup (80g) honey into the yeast mixture, then gradually add the flours. If necessary, add an additional bit of flour if the dough is too wet, or another tablespoon of water if the dough is too dry. It should feel soft and moist, and when you touch it, your finger should just barely stick to it.
3. Knead the dough at low-to-medium speed until smooth, about 6 minutes.
4. Scrape the dough out onto a lightly floured countertop and knead in the sunflower seeds thoroughly, making sure that they are evenly dispersed throughout the dough. Return the dough to the mixer bowl, cover with plastic wrap or a dish towel, and let rise in a warm place until doubled, 1 1/2 to 2 hours.
5. Punch the dough down with your fist, cover, and let rise again until doubled, about 1 hour.
6. Lightly grease a 9-inch (23cm) loaf pan. Scrape the dough onto a lightly floured countertop, shape the dough into a elongated rectangle, and place the dough in the pan. Cover and let rise 1 hour. (Note that it won’t rise much.)
7. About 15 minutes before you plan to bake the bread, preheat the oven to 350ºF (180ºC).
8. When the dough is ready, bake it for 45 minutes to 1 hour. It’ll sound hollow when you tap it in the center. To be sure, you can use an instant-read thermometer; the bread is done when the temperature in the center is 190ºF (88ºC). Remove the bread from the oven and let cool for 20 minutes, then tilt the bread onto a cooling rack and let cool completely before slicing.