Grilled Mushroom and Walnut Patties with Caramelized Onion Aioli

By AislePrompt Editorial · Published 2026-04-09 · Updated 2026-04-09

Savory plant-based patties with earthy mushrooms and toasted walnuts, grilled until crisp and served with a sweet-savory aioli made from deeply caramelized onions. This American-inspired vegetarian recipe, ready in about 55 minutes, pairs cremini mushrooms, walnuts, breadcrumbs for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 385 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Ingredients

• 8 oz cremini mushrooms
• 1/2 cup walnuts
• 1/4 cup breadcrumbs
• 1 large egg
• 1 tbsp olive oil
• 1/2 tsp dried thyme
• 1/2 tsp garlic powder
• to taste salt
• to taste black pepper
• 1 small onion
• 1/2 tsp honey
• 1/2 cup plain yogurt
• 2 cups arugula
• 4 burger buns

Grilling tools worth buying → Best Grilling Tools and BBQ Gadgets for 2026: Top Picks + Buying Guide

Instructions

1. Step 1: Combine 8 oz finely chopped cremini mushrooms, 1/2 cup toasted and chopped walnuts, 1/4 cup breadcrumbs, 1 large egg, 1 tbsp olive oil, 1/2 tsp dried thyme, 1/2 tsp garlic powder, and salt and pepper to taste in a bowl. Mix until evenly incorporated, then form into 4 equal patties.
2. Step 2: Heat a grill pan over medium-high heat. Lightly oil the surface. Place patties on the grill and cook for 4-5 minutes per side until golden brown and heated through.
3. Step 3: In a small skillet, heat 1 tbsp olive oil over medium heat. Add 1 finely sliced small onion and cook, stirring occasionally, for 15-20 minutes until deeply golden and caramelized. Stir in 1/2 tsp honey, salt, and pepper, then remove from heat and let cool.
4. Step 4: Mix the cooled caramelized onions with 1/2 cup plain yogurt in a small bowl. Season with salt and pepper to taste.
5. Step 5: Toast the burger buns if desired. Place a grilled patty on each bun, top with 1/2 cup arugula, and drizzle with the caramelized onion aioli.