• Peel and thinly slice enough onion to measure ¾ cup [1½ cups]. Finely chop enough of the remaining onion to measure 2 tablespoons [¼ cup]; set aside for the sloppy joe filling.

In a small sauce pot, bring the quick-pickle brine and 1 tablespoon [2 TBL] water to a boil. Remove from the heat, add the thinly sliced onion, and season with salt and pepper. Cover and let stand, stirring occasionally, while you prepare the rest of the meal.

In a large frying pan over medium-high heat, warm 1 to 2 teaspoons oil until hot but not smoking. Place the buns, cut sides down, and cook until lightly toasted, 1 to 2 minutes. Transfer to a plate. Do not clean the pan.

• Rinse the lentils.

In the same pan used for the buns, warm 1 to 2 tablespoons oil over medium-high heat until hot but not smoking. Add the finely chopped onion, season with salt and pepper, and cook, stirring occasionally, until the onion starts to soften, 2 to 4 minutes. Add the lentils, green chiles, sloppy joe sauce base, 2 tablespoons [¼ cup] water, and up to 1 teaspoon [2 tsp] brown sugar (from your pantry), if using. Bring to a boil, reduce to a simmer, and cook, stirring occasionally, until the lentils are warmed through and the sauce is thickened slightly, 2 to 3 minutes. If you prefer a saucier filling, stir in more water, 1 tablespoon at a time, to reach the desired consistency. Remove from the heat and season to taste with salt and pepper.
While the sloppy joe filling cooks, prepare the coleslaw.

• Cut away any core from the cabbage; thinly slice the cabbage.
• Drain the pickled onion.

In a large bowl, stir or whisk together the coleslaw dressing base and 1 tablespoon [2 TBL] oil; season to taste with salt and pepper. Add the cabbage, pickled onion, and carrots and toss to combine. Season to taste with salt and pepper.

Place the bun tops and bottoms, cut sides up, on individual plates. Top with the sloppy joe filling and some of the coleslaw to make open-faced sandwiches. Serve the remaining coleslaw on the side.