Portobello Sliders with Pepita Pesto

Name: Portobello Sliders with Pepita Pesto
Ingredients: For the pepita pesto:; 1/2 cup pepitas (pumpkin seeds); 1 garlic clove; Salt and pepper, to taste; 2 teaspoons fresh lemon juice; 2 cups cilantro (or basil); 1/2 teaspoon ground cumin; 1/4 cup extra-virgin olive oil, plus more to taste; 1/4 teaspoon honey, optional (skip or replace with agave if vegan); For the portobello sliders:; 8 small portobello mushrooms; Extra-virgin olive oil, for drizzling; Balsamic vinegar, for drizzling; Tamari, for drizzling; Pepper, to taste; 8 slider buns, toasted; 1 tomato, sliced; 1/2 cup microgreens; Freshly ground black pepper