Slow Cooker Tempeh Sloppy Joes: Easy, Irresistible Recipe

Slow cooker tempeh makes a hearty filling for vegan sloppy joes, with small, tender crumbles coated in a thick tomato sauce. Bell peppers, onion, smoked paprika, and a little vinegar give these sandwiches a tangy barbecue flavor without bottled barbecue sauce. A brief sauté gets the vegetables started, then the slow cooker takes over. Serve the filling on toasted whole grain buns, with pickles and something crisp alongside.

Choosing and preparing the tempeh

Plain tempeh works best here because the sauce supplies plenty of seasoning. Tempeh is made from fermented soybeans, sometimes with added grains, and has a firm texture that holds up during slow cooking. Unlike cooked lentils, it keeps a noticeable bite in the finished sandwich filling.

Break the tempeh into roughly pea-size pieces with your fingers, or chop it with a knife. A mixture of smaller crumbs and slightly larger pieces gives the filling texture without making the sandwiches difficult to eat. Avoid processing it into a paste.

Some brands taste more bitter than others. If that bothers you, steam the blocks for about 10 minutes before crumbling. This optional step can soften that flavor, though it isn’t necessary for every brand. Follow any cooking directions on the package.

Slow cooker tempeh recipe

This recipe uses a small slow cooker and makes enough filling for six generous sandwiches. Sautéing the vegetables first helps them soften evenly and gives the onion a sweeter flavor.

Yield: 6 sandwiches
Preparation time: 15 minutes
Stovetop cooking: About 10 minutes
Slow cooking: 3–4 hours on low or 2–3 hours on high
Total time: About 3 hours 25 minutes to 4 hours 25 minutes on low
Equipment: A 3-quart slow cooker, large skillet, cutting board, and knife

Ingredients

– 1 tablespoon (15 ml) olive oil
– 1 medium yellow onion, finely diced, about 1 cup (150 g)
– 1 large bell pepper, finely diced, about 1 cup (150 g)
– 3 garlic cloves, minced
– 2 teaspoons smoked paprika
– 1 teaspoon ground cumin
– ¼ teaspoon freshly ground black pepper
– 16 ounces (454 g) plain tempeh, crumbled
– 1 can (15 ounces/425 g) plain tomato sauce, preferably no-salt-added
– ½ cup (120 ml) ketchup
– ¼ cup (60 ml) water
– 2 tablespoons (30 ml) apple cider vinegar
– 2 tablespoons (30 ml) reduced-sodium soy sauce
– 1 tablespoon (15 ml) prepared yellow mustard
– 1 tablespoon (15 ml) maple syrup, optional, to taste
– Salt, if needed
– 6 whole grain buns, checked for vegan ingredients
– Sliced pickles, thinly sliced onion, or cabbage slaw, optional, for serving

Use plain canned American-style tomato sauce, not concentrated tomato paste. A red bell pepper adds sweetness; a green one gives the filling a slightly sharper, more traditional sloppy joe flavor.

Instructions

1. Soften the vegetables. Heat the olive oil in a large skillet over medium heat. Add the onion and bell pepper. Cook for 6–8 minutes, stirring occasionally, until the onion is translucent and the pepper begins to soften.

2. Add the seasonings. Stir in the garlic, smoked paprika, cumin, and black pepper. Cook for about 30 seconds, just until fragrant. Transfer the mixture to the slow cooker.

3. Mix the filling. Add the crumbled tempeh, tomato sauce, ketchup, water, vinegar, soy sauce, and mustard. Stir thoroughly, breaking apart any large clumps of tempeh. Reserve the optional maple syrup until the end so you can judge how much sweetness the sauce needs.

4. Slow-cook until tender. Cover and cook on low for 3–4 hours or high for 2–3 hours. Begin checking at the earlier time. The vegetables should be tender, the filling hot throughout, and the tempeh well coated with sauce. Slow cookers vary, so use those signs along with the clock.

5. Check the consistency and seasoning. Stir well. If the mixture looks dry, add water a tablespoon at a time. If it is too loose for a sandwich, transfer it to a skillet and simmer uncovered for several minutes, stirring frequently. Taste before adding salt. Add some or all of the maple syrup if you prefer a sweeter sauce.

6. Toast and fill the buns. Toast the cut sides of the buns in a dry skillet or under the broiler, watching closely. Spoon on the hot filling and add any toppings just before serving.

Getting the sauce right

Sloppy joe filling should be moist enough to spread but thick enough to stay mostly inside the bun. Drag a spoon through the finished mixture: the path should remain briefly visible before the sauce settles back. A puddle of thin liquid around the crumbles means the filling needs a little more reduction.

The final seasoning depends partly on the ketchup. Some brands are much sweeter or saltier than others, which is why the maple syrup and extra salt are added last. For a sharper sauce, stir in another teaspoon of cider vinegar after cooking. For heat, add a pinch of cayenne or a few dashes of hot sauce.

Avoid increasing the smoked paprika too freely. Its smoky flavor can become overpowering, especially after several hours in the sauce.

Serving and saving the filling

Toasted whole grain buns hold up better than soft, untoasted bread, though these are still fork-nearby sandwiches. Pickles bring acidity, and a lightly dressed cabbage slaw adds crunch. Roasted potato wedges or a simple cucumber salad make practical sides.

The filling also works over a baked potato or rice, making leftovers useful for another plant-based dinner without repeating the sandwich.

Refrigerate leftovers in shallow, covered containers within two hours of cooking, or within one hour if the temperature is above 90°F (32°C). Keep refrigerated for 3–4 days, or freeze in meal-size portions for about 2–3 months for best quality.

Reheat refrigerated or thawed filling in a saucepan over medium-low heat, adding a splash of water as needed. Stir frequently and heat to 165°F (74°C). A slow cooker is not recommended for reheating cold leftovers because they may warm too slowly. Store the buns separately so they don’t absorb the sauce before serving.