Remove fries from packaging and place on a baking sheet lined with aluminum foil that’s been lightly brushed with oil or parchment paper, leaving space between fries. Place on center rack in oven and bake for 18-20 minutes.
While fries cook, prepare mushrooms.
To prepare thawed burgers, preheat grill to medium-high (400-450 degrees Fahrenheit). Clean and oil grill grates, then grill burgers for 5-6 minutes per side.
Place a slice of pepper jack cheese on each burger just before removing from the grill.
Assembly: Place 1/4 cup of arugula on each bottom bun, add burger, generously and evenly top with mushrooms, add red onion slice, and finish with top bun.
Serve with fries.
Sautéed Wild Mushrooms
Heat a large saucepan over high.
Add canola oil, then add garlic and shallots and cook until transparent.
Add mushrooms and thyme and sauté for 4-5 minutes.