Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 450 degrees. Wash and dry all produce. • Halve, peel, and thinly slice onion; mince a few slices until you have 2 TBSP (4 TBSP for 4). Dice tomato. Roughly chop cilantro. Quarter lime. Halve, core, and thinly slice green pepper into strips. • In a small bowl, combine minced onion, tomato, half the cilantro, and a squeeze of lime juice. Season with salt and pepper. • In a separate small bowl, combine sour cream with a squeeze of lime juice. Season with salt and pepper. Stir in water 1 tsp at a time until mixture reaches a drizzling consistency.

Drizzle tortillas with 1 TBSP olive oil (2 TBSP for 4 servings); brush or rub to coat all over. Arrange on a baking sheet in a single layer (divide between 2 sheets for 4). Gently prick each tortilla in a few places with a fork. • Bake on top rack, flipping halfway through, until lightly golden, 4-5 minutes per side. (For 4, bake on top and middle racks; flip tortillas and swap rack positions halfway through cooking.) TIP: Watch carefully to avoid burning.

While tortillas bake, heat a drizzle of oil in a large pan over medium-high heat. Add green pepper, sliced onion, and half the Southwest Spice (you’ll use the rest in the next step). Cook, stirring occasionally, until lightly charred and softened, 5-7 minutes. Season with salt and pepper. • Turn off heat; transfer to a plate.

Meanwhile, drain and rinse beans. • Heat pan used for veggies over medium-high heat. Add beans, Tex Mex paste, remaining Southwest Spice, and ¼ cup water (⅓ cup for 4 servings). Bring to a simmer and cook until liquid has mostly evaporated, 3-4 minutes. • Remove from heat and gently mash beans with a potato masher or back of a spoon. Stir in 1 TBSP butter (2 TBSP for 4). If mixture is too thick, add a splash of water. Season with salt and pepper.

Once tortillas are toasted, remove sheet from oven. Carefully spread each tortilla with smashed beans, then top with veggies and Mexican cheese. • Return to oven until cheese melts, 2-3 minutes.

Divide tostadas between plates. Top with pico de gallo, lime crema, and remaining cilantro. Serve with remaining lime wedges on the side.