Combine the first 4 ingredients in a large bowl, and add 2 cups boiling water, stirring until well blended. Cool to room temperature.
Dissolve yeast in 1/3 cup warm water in a small bowl; let stand 5 minutes.
Add yeast mixture to oats mixture; stir well.
Stir in flaxseed meal.
Gradually add 3 cups whole wheat flour and 1 cup all-purpose flour to oats mixture; stir until a soft dough forms.
Turn dough out onto a lightly floured surface. Knead until smooth and elastic (about 8 minutes); add enough of remaining all-purpose flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky).
Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in size.
Punch dough down, and let rest for 5 minutes.
Divide dough in half; cut each half into 12 equal portions.
Working with one portion at a time (cover remaining dough to prevent from drying), shape each portion into an 8-inch rope. Tie each rope into a single knot; tuck top end of rope under bottom edge of roll.
Place each roll on a baking sheet coated with cooking spray.
Cover with plastic wrap coated with cooking spray; let rise in a warm place (85F), free from drafts, for 30 minutes or until doubled in size.
Preheat oven to 400°F.
Combine 1 teaspoon water and egg in a small bowl; brush egg mixture over rolls.
Combine 1 tablespoon oats, poppy seeds, and sesame seeds; sprinkle evenly over rolls.