Cook the Potatoes: Place the baby potatoes in a microwave-safe bowl and microwave on high for 5 to 8 minutes, or until fork-tender. Allow them to cool slightly before handling.
Slice the Sausage: Place the smoked sausage on a cutting board and slice it into evenly sized pieces, about 1 inch thick. This helps the sausage cook evenly and makes it easier to thread onto skewers.
Prepare the Onion: Peel the yellow onion and cut it into large, bite-sized chunks. Keep the pieces thick enough to hold their shape during grilling.
Assemble the Skewers: Thread the cooked baby potatoes, smoked sausage pieces, and onion chunks onto wooden skewers, alternating the ingredients. Leave a little space between the pieces to help them brown evenly.
Add the Dark Beer: Pour ½ cup of dark beer into a medium mixing bowl to create the base of the glaze.
Mix in the Maple Syrup: Add ¼ cup of maple syrup to the dark beer.
Season the Glaze: Sprinkle in ¼ teaspoon of freshly ground black pepper and ¼ teaspoon of crushed red pepper flakes.
Whisk the Glaze: Whisk the beer, maple syrup, and seasonings together until well combined and smooth.
Brush the Skewers: Arrange the assembled skewers on a baking sheet. Use a pastry brush to generously coat the sausage, potatoes, and onions with the glaze, reserving some for brushing during grilling.
Preheat the Grill Pan: Place a grill pan over medium-high heat and allow it to preheat for 2 to 3 minutes until hot.
Grill the Skewers: Carefully place the skewers onto the hot grill pan using kitchen tongs. Cook for 8 to 10 minutes, turning every few minutes to brown the sausage and develop grill marks on the potatoes and onions.
Apply More Glaze: While grilling, brush the skewers with the remaining beer and maple syrup glaze. Turn them occasionally to distribute the glaze evenly and prevent the maple syrup from burning.
Finish Cooking: Continue grilling for another 2 to 3 minutes, or until the sausage is heated through, the onions are slightly tender, and the glaze has thickened into a shiny coating. Adjust the heat to medium if the glaze begins to darken too quickly.
Serve the Skewers: Remove the skewers from the grill pan and transfer them to a serving platter. Serve warm while the sausage is juicy, the potatoes are tender, and the glaze is sticky and caramelized.