Begin with boiling a small potato and set it aside to cool.
1/2 small potato
Place the flour in the bowl of a mixer and make a small well in the center. Put the yeast in the center of the well and sprinkle the sugar over the whole mixture (so some gets on the yeast). Place the salt on the edges of the bowl, not touching the yeast. Pour about 2 Tbsp of the warm water on the yeast and let it sit for about 10 minutes.
2 cup (250g) all-purpose flour, 1/2 envelope active dry yeast, 1 Tbsp granulated sugar, 1/2 tsp salt, 1/3 cup (80mL) warm water
Meanwhile, warm up the milk and mix it with the warm water, oil, sour cream and egg yolk. (It shouldn't be too hot that it cooks the egg yolk). Peel the potato and smash or grate it into the liquid mixture,
3/4 cup (180mL) warm milk, 1/4 cup (60mL) canola oil, 1 Tbsp sour cream, 1 egg yolk
By now the yeast and water should have foamed up a little. With the hook attachment, start the mixture on low-medium speed and slowly begin pouring in the liquid mixture.
The dough will be quite sticky when it's come together. Grease the sides of the bowl so the dough doesn't stick as much when you try to remove it. Cover it and place it in a warm environment to rise until it's doubled, about 1 hour.
Once the dough has doubled, remove it from the bowl and separate it into four sections. Spread each one to about 10-12" in diameter and then slice it into 8 triangles, like a pizza.
Spread about 1 tsp of jam onto each triangle (keeping it only on the wide half), then start with the back end and go towards the tip and roll TIGHLY into the shape of a croissant. Then shape them into a crescent shape and let them rise on the baking pan for about 15-20 minutes.
1 cup (320g) apricot jam
Preheat the oven to 350F/177C convection (325F/163C conventional). Bake for about 30 minutes, until they're a nice golden brown.
Serve them warm or at room temperature. Store the left overs in an airtight container or plastic bag.